MAIDENHEAD METEOROLOGICAL OBSERVATIONS FOR JANUARY 1999
-09GMT- --Temperature- --Soil temps-- -Earth temps-- Rain Fr. Pch
DD N dd ff ww VV Temp RH Max Min Gmin 5cm 10cm 20cm 30cm 50cm 1m E SS Rain Sun SLHTGF Press hrs hrs Evap
-----------------------------------------------------------------------------------------------------------------
01 7 21 05 02 97 7.6 94 10.1 5.8 -0.2 6.2 6.2 6.8 7.0 7.0 7.6 10 0 3.0 1.9 000000 1006.5 3.4 0.0 1.0
02 1 23 05 02 97 7.6 84 9.4 7.3 2.8 6.1 6.1 6.8 7.0 7.0 7.8 10 0 11.4 5.6 000000 996.5 4.0 0.0 0.8
03 7 30 02 21 96 8.6 92 13.5 2.9 -1.7 5.6 5.1 5.5 6.5 6.8 7.7 20 0 5.7 2.3 000000 991.5 6.9 0.0 0.7
04 7 21 13 02 97 12.0 89 12.5 6.5 1.5 8.9 8.1 7.2 6.7 6.6 7.7 10 0 0.7 0.9 000000 1004.5 1.0 0.0 1.4
05 8 21 13 02 97 12.5 82 13.7 9.8 4.9 9.3 8.8 8.3 7.6 7.1 7.7 10 0 0.0 0.2 000000 1011.5 0.0 0.0 1.8
06 4 22 09 02 97 12.5 76 14.2 10.2 4.5 7.0 7.1 7.7 8.0 7.5 7.8 10 0 2.9 2.3 000000 1010.0 2.9 0.0 1.4
07 7 31 02 02 96 4.0 97 8.1 2.6 -2.3 4.6 5.1 7.1 7.9 7.6 8.0 10 0 6.7 1.7 000000 1011.0 4.1 0.0 0.6
08 0 02 02 02 97 1.4 90 7.8 1.4 -2.4 3.8 4.2 6.0 7.1 7.4 8.0 10 0 6.1 1.6 000000 1006.0 4.2 0.0 0.4
09 2 03 09 02 97 2.0 93 4.3 1.4 -2.7 3.2 3.6 5.3 6.5 6.9 8.0 10 0 tr 1.2 000000 1015.0 0.0 0.0 0.7
10 8 31 05 02 97 2.0 88 3.6 0.7 -3.5 3.2 3.2 4.6 6.0 6.5 7.9 10 0 tr 1.7 000000 1018.5 0.0 0.0 0.6
11 1 00 00 02 97 0.5 96 2.7 -1.5 -5.6 1.2 1.8 3.8 5.4 5.9 7.7 40 0 0.5 0.8 100000 1020.0 1.8 6.6 0.5
12 8 21 02 70 95 2.0 97 6.2 -2.5 -7.1 0.5 1.3 2.9 4.6 5.5 7.4 X1 0 9.1 1.0 500000 1008.5 5.0 7.3 0.5
13 7 25 02 03 97 4.1 88 8.3 2.0 -1.8 1.3 1.5 2.9 4.4 5.1 7.2 10 0 1.1 0.0 000000 1012.0 1.3 0.0 0.7
14 0 31 05 02 97 3.3 91 9.5 3.3 -1.7 2.4 2.7 3.9 4.6 4.7 6.9 10 0 1.1 5.7 000000 1011.0 1.7 0.0 1.2
15 7 22 05 02 97 9.5 82 11.3 3.3 1.8 5.1 4.4 4.7 5.0 5.2 6.8 10 0 16.1 0.0 000000 1006.5 15.8 0.0 1.1
16 7 27 05 02 97 5.9 88 8.1 5.9 2.2 7.2 7.1 6.9 6.1 5.5 6.7 10 0 0.0 4.6 000000 998.0 0.0 0.0 0.9
17 1 36 02 02 97 0.4 96 8.8 0.4 -4.4 2.3 2.7 4.7 5.9 5.9 6.9 10 0 0.0 5.5 000000 1006.0 0.0 0.0 0.9
18 1 20 05 02 97 3.9 86 11.3 -1.8 -4.5 1.1 1.6 3.2 5.1 5.3 6.8 10 0 6.1 1.6 000000 1018.0 8.0 8.2 0.9
19 8 22 19 50 96 11.3 94 12.4 3.9 7.3 7.3 6.9 6.3 5.6 5.2 6.8 10 0 4.1 0.0 000000 1008.5 15.0 0.0 0.7
20 8 21 19 50 96 12.0 88 12.0 11.3 9.8 9.7 8.9 8.1 7.2 6.0 6.8 10 0 0.1 0.0 000000 1010.0 0.4 0.0 0.5
21 9 00 00 45 01 2.9100 6.7 2.9 0.1 6.2 6.4 7.2 7.4 6.8 7.1 10 0 0.3 0.0 000001 1022.5 0.2 0.0 0.1
22 9 00 00 45 01 -2.0100 2.3 -2.4 -2.3 2.8 3.3 5.1 6.7 6.6 7.2 10 0 0.1 0.0 000001 1029.0 0.1 18.0 0.1
23 8 00 00 10 94 2.2 98 9.1 -2.0 -1.1 3.4 3.4 4.6 5.8 6.3 7.2 10 0 1.3 0.0 000000 1020.0 1.9 6.0 0.6
24 7 27 02 02 94 5.8 93 12.5 2.2 -1.9 4.2 4.4 5.7 6.1 6.1 7.1 10 0 0.2 0.0 000000 1019.5 0.2 0.0 0.8
25 8 23 09 60 97 12.4 91 12.6 5.8 7.0 8.8 8.1 7.3 6.7 6.3 7.0 10 0 5.4 0.6 000000 1010.0 1.0 0.0 1.1
26 7 23 05 03 97 6.0 83 8.8 3.2 -1.5 4.8 4.8 6.0 6.9 6.7 7.1 10 0 5.7 1.5 000000 1013.0 3.1 0.0 1.1
27 0 30 02 02 97 3.0 95 11.0 1.8 -1.7 2.9 3.3 5.1 6.4 6.5 7.2 10 0 0.4 3.1 000000 1017.0 2.2 0.0 1.0
28 8 30 13 60 97 11.0 88 11.0 3.0 6.2 7.2 6.7 6.6 6.5 6.3 7.1 10 0 1.4 4.3 000000 1011.5 1.8 0.0 1.4
29 7 31 02 02 96 3.0 97 6.8 0.9 -3.1 3.9 3.6 5.2 6.5 6.4 7.1 10 0 2.9 0.0 000000 1030.5 8.7 0.0 0.3
30 8 00 00 61 94 4.5 98 4.8 3.0 1.0 5.4 5.3 5.9 6.4 6.3 7.1 10 0 2.8 0.0 000001 1038.0 5.9 0.0 0.3
31 8 00 00 02 96 4.1 89 7.1 3.7 3.1 4.8 4.7 5.5 6.0 6.2 7.1 10 0 tr 0.0 000000 1042.0 0.0 0.0 0.4
-----------------------------------------------------------------------------------------------------------------
Mean
5.5 5.2 5.7 91 9.0 3.1 0.1 4.9 4.9 5.7 6.3 6.3 7.3 1013.6
Total 95.2 48.1 100.6 46.1 24.5
1961-1990 Climatological
Mean5.5 6.7 89 7.1 1.1 -0.8 3.3 3.3 4.1 4.7 5.4 6.6 57.3 46.4 1015.1 57
-----------------------------------------------------------------------------------------------------------------
Snow days 2; mean 3.6; 50% snow cover at 09h days 0; mean 3.5;
Hail days 0; mean 0.0; Ice pellets days 0; mean 0.3;
Thunder days 0; mean 0.3; Fog at 09h days 3; mean 2.5;
Gale days 0; mean 0.7;
Air frost days 5; mean 11.5; Days with 0.2mm rain days 23; mean 17.2*
Grass minimum frost days 18; mean 17.8; Days with 1.0mm rain days 18; mean 11.9*
Soil frost days 7 Days with 5.0mm rain days 9; mean 4.8*
Concrete frost days 7 Days with no sun days 11; mean 14.0
Air pressure: max - 1043.0mb/31st, min - 990.0mb/16th
Key
DD: date
07GMT observations...
N cloud cover (oktas, 9=obscured); dd wind direction (degrees/10); ff wind speed (knots);
VV visibility (00-50 metres/100, 94 very poor, 95 poor, 96 moderate, 97 good);
Soil temperatures are for 07GMT beneath a bare soil surface (degC);
Earth temperatures are for 07GMT beneath a grass surface (degC); SS snow depth (cm)
ww present weather code (02 sky not changing, 03 cloud increasing, 10 mist,
21 recent rain, 45 fog, 50 intermittent light drizzle, 60 intermittent light rain,
61 continous light rain)
09GMT observations...
Temp temperature (degC); RH relative humidity (%);
Press air pressure (mb); E state of ground (00 dry, 10 moist, 20 wet, 40 frozen, 50 glaze, X1 snow lying;
24 hour readings...
Max maximum temperature (degC) beginning 09GMT, Min minimum temperature (degC) ending 09GMT;
Gmin grass minimum temperature (degC) ending 09GMT; Pch Evap Piche evapoartion (ml) beginning O9GMT;
Rain rainfall beginning 09GMT (mm); Sun sunshine (hours) sunrise-sunset;
Rain hrs hours of rainfall (>0.1mm/hr) 09-09GMT; Fr. hrs hours of air frost (00-24GMT)
Days with...
S snow/sleet falling; L 50% snow cover at 09GMT; H>4 hail falling;
H<5 ice pellets, snow grains, snow pellets falling; T thunder heard;
G gale; F fog at 09GMT;
* Averages for Hurley (4km away)
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MAIDENHEAD METEOROLOGICAL OBSERVATIONS FOR FEBRUARY 1999
-09GMT- --Temperature- --Soil temps-- -Earth temps-- Rain Fr. Pch
DD N dd ff ww VV Temp RH Max Min Gmin 5cm 10cm 20cm 30cm 50cm 1m E SS Rain Sun SLHTGF Press hrs hrs Evap
-----------------------------------------------------------------------------------------------------------------
01 8 31 02 02 96 7.1 93 9.7 4.1 3.1 5.8 5.4 5.9 6.0 6.2 7.1 10 0 0.0 0.0 000000 1041.5 0.0 0.0 0.8
02 2 02 02 10 96 4.7 97 10.0 4.7 0.2 5.8 5.8 6.4 6.4 6.2 7.1 10 0 0.0 3.2 000000 1041.5 0.0 0.0 0.6
03 7 05 02 02 96 5.8 97 10.9 4.0 -1.2 4.4 4.4 5.7 6.5 6.3 7.1 10 0 0.0 0.0 000000 1036.0 0.0 0.0 1.0
04 8 29 09 03 97 10.5 81 12.6 5.8 5.4 7.4 7.0 7.0 6.9 6.4 7.1 10 0 0.0 2.9 000000 1030.0 0.0 0.0 1.4
05 7 33 05 02 97 7.3 75 9.8 6.9 2.1 5.6 5.8 6.9 7.1 6.7 7.1 10 0 tr 0.9 000000 1022.5 0.0 0.0 1.8
06 6 36 05 02 97 6.4 81 9.0 6.3 1.5 5.7 5.6 6.3 6.9 6.7 7.3 10 0 3.8 0.4 000000 1019.0 4.1 0.0 1.0
07 0 36 13 02 97 2.3 72 5.5 2.3 -2.0 3.4 4.0 5.7 6.7 6.7 7.3 10 0 0.0 7.9 000000 1011.0 0.0 0.0 1.7
08 7 24 05 03 97 0.5 89 2.8 -0.6 -5.0 1.7 2.0 3.9 5.6 6.2 7.3 10 0 1.1 0.2 500000 1008.0 3.4 3.2 0.3
09 0 32 13 02 97 -1.0 79 3.7 -1.7 -5.0 1.1 1.5 3.3 5.0 5.6 7.1 x2 .5 0.0 7.7 010000 1008.0 0.0 14.0 1.3
10 0 32 12 02 97 0.9 82 5.0 -1.8 -7.2 0.6 0.8 2.5 4.1 5.0 6.9 40 0 0.0 7.8 000000 1014.5 0.0 10.7 1.1
11 0 32 02 02 97 -1.0 98 6.0 -4.2 -8.6 0.4 0.7 2.2 3.6 4.4 6.6 10 0 0.9 1.7 000000 1024.5 1.5 9.5 0.8
12 7 22 05 02 96 3.2 96 7.9 -1.0 -0.5 2.9 2.6 3.2 4.0 4.3 6.4 10 0 0.0 0.6 000000 1028.5 0.0 0.0 0.5
13 8 21 02 02 97 4.0 78 8.6 3.2 1.2 3.7 3.4 4.1 4.4 4.6 6.2 10 0 0.0 7.5 000000 1036.0 0.0 1.6 0.5
14 3 18 02 03 96 1.2 76 8.4 -4.8 -8.8 1.0 1.2 3.0 3.8 4.6 6.1 10 0 3.5 0.0 000000 1035.0 1.4 8.7 0.5
15 3 31 02 10 94 3.5 93 10.4 1.2 -0.5 1.9 2.2 3.5 3.9 4.4 6.1 10 0 0.9 3.5 000000 1027.5 0.2 0.0 1.4
16 5 31 09 01 97 7.1 58 11.4 3.1 1.0 4.2 4.5 4.9 5.0 4.8 6.1 10 0 0.7 5.5 000000 1019.0 0.5 0.0 3.0
17 7 31 09 60 97 4.1 84 11.1 1.3 1.5 3.8 3.9 4.5 5.2 5.1 6.2 10 0 1.4 1.5 000000 1020.5 3.3 0.0 1.7
18 7 27 09 02 97 11.1 90 13.0 4.1 3.0 6.2 6.3 6.5 5.8 5.3 6.2 10 0 0.6 0.5 000000 1020.5 1.6 0.0 1.4
19 8 22 09 21 97 11.5 92 13.7 9.2 6.0 8.0 8.4 7.5 6.7 5.8 6.3 10 0 tr 0.0 000000 1015.5 0.0 0.0 0.9
20 4 00 00 02 97 6.6 84 11.5 5.0 -1.0 6.2 6.6 7.5 7.2 6.3 6.4 10 0 1.4 7.9 000000 1020.0 1.8 0.0 1.9
21 7 32 09 21 97 8.7 80 11.7 6.1 3.7 6.7 6.4 6.8 7.1 6.7 6.7 10 0 1.8 4.0 004000 1008.0 0.7 0.0 1.8
22 4 32 19 25 97 3.4 82 8.4 2.1 -0.1 3.3 3.8 5.6 6.8 6.5 6.9 10 0 tr 8.3 504000 1007.5 0.0 0.0 2.3
23 0 34 05 02 97 3.5 82 9.0 1.5 -2.4 1.9 2.4 4.3 6.0 6.3 6.9 10 0 2.7 6.5 000000 1019.5 7.2 0.0 1.0
24 8 36 02 02 94 4.8 98 6.5 2.5 2.0 3.9 4.5 5.3 5.9 6.0 6.9 10 0 0.0 1.9 000000 1009.5 0.0 0.0 0.4
25 8 27 02 02 96 1.8 96 9.5 -1.2 -4.3 2.8 2.8 4.1 5.6 5.8 6.7 10 0 0.0 0.0 000000 1022.5 0.0 3.6 0.9
26 8 25 05 02 96 9.5 91 10.1 1.8 3.9 6.7 6.1 6.0 5.9 5.7 6.6 10 0 7.3 0.0 000000 1016.0 13.5 0.0 0.2
27 8 23 02 02 96 7.5 96 10.7 6.8 3.5 6.6 6.4 6.9 6.5 6.1 6.6 10 0 0.0 5.9 000000 1010.0 0.0 0.0 1.3
28 7 36 02 02 97 5.9 88 12.2 2.4 -2.2 3.8 3.8 5.3 6.4 6.3 6.7 10 0 2.9 3.2 000000 1020.0 6.5 0.0 0.8
-----------------------------------------------------------------------------------------------------------------
Mean
5.3 5.8 5.0 86 9.3 2.5 -0.4 4.1 4.2 5.2 5.8 5.8 6.7 1021.1
Total 29.0 89.5 45.7 51.3 32.3
1961-1990 Climatological
Mean5.7 6.5 88 7.8 1.3 -1.3 2.9 3.3 4.1 4.6 5.1 6.0 39.3 65.2 1015.5 43
-----------------------------------------------------------------------------------------------------------------
Snow days 2; mean 3.4; 50% snow cover at 09h days 1; mean 2.1;
Hail days 0; mean 0.2; Ice pellets days 2; mean 0.4;
Thunder days 0; mean 0.2; Fog at 09h days 0; mean 2.0;
Gale days 0; mean 0.4;
Air frost days 7; mean 10.0; Days with 0.2mm rain days 13; mean 12.6*
Grass minimum frost days 14; mean 17.7; Days with 1.0mm rain days 9; mean 8.4*
Soil frost days 7 Days with 5.0mm rain days 1; mean 3.0*
Concrete frost days 8 Days with no sun days 6; mean 9.5
Air pressure: max - 1042.0mb/1st, min - 1002.0mb/8th
Key
DD: date
07GMT observations...
N cloud cover (oktas, 9=obscured); dd wind direction (degrees/10); ff wind speed (knots);
VV visibility (00-50 metres/100, 94 very poor, 95 poor, 96 moderate, 97 good);
Soil temperatures are for 07GMT beneath a bare soil surface (degC);
Earth temperatures are for 07GMT beneath a grass surface (degC); SS snow depth (cm)
ww present weather code (01 cloud decreasing, 02 sky not changing, 03 cloud increasing,
10 mist, 21 recent rain, 25 recent rain shower, 60 intermittent light rain)
09GMT observations...
Temp temperature (degC); RH relative humidity (%);
Press air pressure (mb); E state of ground (00 dry, 10 moist, 20 wet, 40 frozen, x2 50% snow cover)
24 hour readings...
Max maximum temperature (degC) beginning 09GMT, Min minimum temperature (degC) ending 09GMT;
Gmin grass minimum temperature (degC) ending 09GMT; Pch Evap Piche evaporation (ml) beginning O9GMT;
Rain rainfall beginning 09GMT (mm); Sun sunshine (hours) sunrise-sunset;
Rain hrs hours of rainfall (>0.1mm/hr) 09-09GMT; Fr. hrs hours of air frost (00-24GMT)
Days with...
S snow/sleet falling; L 50% snow cover at 09GMT; H>4 hail falling;
H<5 ice pellets, snow grains, snow pellets falling; T thunder heard;
G gale; F fog at 09GMT;
* Averages for Hurley (4km away)
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MAIDENHEAD METEOROLOGICAL OBSERVATIONS FOR MARCH 1999
-09GMT- --Temperature- --Soil temps-- -Earth temps-- Rain Fr. Pch
DD N dd ff ww VV Temp RH Max Min Gmin 5cm 10cm 20cm 30cm 50cm 1m E SS Rain Sun SLHTGF Press hrs hrs Evap
-----------------------------------------------------------------------------------------------------------------
01 8 22 09 02 97 11.9 93 13.5 5.9 7.9 8.6 8.2 7.7 7.0 6.5 6.8 10 0 0.7 0.2 000000 1009.0 2.4 0.0 0.8
02 8 25 02 02 96 11.8 95 15.3 11.2 7.8 9.6 9.1 8.9 7.9 7.0 6.9 10 0 4.5 0.6 000000 1008.0 3.6 0.0 1.3
03 6 23 09 02 97 8.0 75 10.8 7.4 3.8 6.6 6.9 8.0 8.2 7.5 7.1 10 0 1.1 5.3 000000 988.5 2.7 0.0 1.6
04 7 30 05 02 97 5.2 92 8.0 4.8 1.1 6.5 6.6 7.4 7.9 7.5 7.4 10 0 0.0 0.1 000000 988.5 0.0 0.0 1.2
05 7 02 09 03 97 4.5 72 5.5 2.7 -1.6 4.8 5.1 6.2 7.4 7.2 7.4 10 0 0.2 0.1 100000 997.0 0.7 0.0 1.4
06 7 35 02 02 97 4.2 80 7.9 2.1 -1.5 4.1 4.2 5.5 6.6 6.8 7.4 10 0 2.0 2.3 000000 1001.5 6.1 0.0 0.6
07 8 01 02 50 96 4.3 93 5.4 2.6 2.4 5.1 5.0 5.9 6.6 6.5 7.4 10 0 4.4 0.0 000000 1002.5 8.7 0.0 0.3
08 7 05 05 02 96 5.0 92 8.3 4.1 2.5 5.3 5.1 5.9 6.5 6.4 7.3 10 0 0.0 2.0 000000 1004.0 0.0 0.0 1.1
09 6 09 05 02 97 4.0 90 10.2 3.5 1.5 4.9 4.9 5.9 6.6 6.5 7.1 10 0 0.0 4.9 000000 1006.5 0.0 0.0 0.9
10 2 00 00 03 96 -0.1 98 8.1 -2.4 -5.4 2.0 2.6 4.7 6.4 6.3 7.1 10 0 0.0 3.6 000000 1015.5 0.0 9.1 0.7
11 6 06 02 02 97 2.0 82 9.6 -1.0 -5.7 1.7 2.2 4.1 5.8 6.2 7.1 10 0 tr 0.5 000000 1017.0 0.0 2.5 1.0
12 0 12 02 02 97 9.6 93 14.0 2.0 0.3 5.3 5.0 5.6 6.0 5.8 6.9 10 0 2.7 0.3 000000 1010.0 2.4 0.0 0.5
13 7 25 02 02 96 10.1 91 14.8 8.8 4.3 7.9 7.6 7.6 7.0 6.3 6.9 10 0 0.0 5.6 000000 1014.5 0.0 0.0 1.2
14 1 05 02 02 97 7.0 83 14.9 -0.1 -2.9 4.9 4.7 6.5 7.5 7.1 7.1 10 0 0.0 8.6 000000 1026.0 0.0 0.2 1.0
15 7 27 02 02 96 8.5 93 15.5 1.9 -0.7 5.4 5.6 6.9 7.5 7.2 7.2 10 0 0.0 6.8 000000 1031.5 0.0 0.0 1.3
16 4 00 00 02 97 7.0 85 16.2 0.8 -1.6 4.6 5.0 6.8 7.8 7.4 7.4 10 0 0.0 6.7 000000 1032.0 0.0 0.0 1.2
17 1 15 02 02 96 11.3 90 20.3 4.5 1.6 6.4 6.6 7.8 8.1 7.7 7.5 10 0 0.0 9.4 000000 1030.5 0.0 0.0 1.5
18 6 04 02 02 96 11.0 89 13.2 5.8 3.9 7.2 7.2 8.5 8.7 8.0 7.6 10 0 0.0 3.9 000000 1025.5 0.0 0.0 2.5
19 8 31 02 03 97 7.3 90 11.9 5.0 1.0 5.9 6.1 7.5 8.4 8.1 7.8 10 0 0.0 2.7 000000 1029.0 0.0 0.0 1.7
20 0 27 02 02 97 8.2 80 11.5 2.1 -1.4 5.0 5.3 7.1 8.0 7.8 7.9 00 0 1.6 2.4 000000 1030.0 2.2 0.0 1.7
21 8 30 02 61 96 8.1 94 13.5 6.9 5.7 7.6 7.4 8.1 8.1 7.8 7.9 10 0 0.4 2.2 000000 1007.5 0.9 0.0 1.7
22 3 25 09 02 97 7.1 61 10.8 5.8 3.3 6.7 6.9 7.9 8.4 8.0 7.9 10 0 0.2 6.3 000000 1018.0 0.5 0.0 1.9
23 6 23 05 02 97 10.7 83 16.4 7.1 5.3 7.9 8.0 8.8 8.6 8.0 8.0 10 0 0.0 4.9 000000 1014.5 0.0 0.0 1.8
24 8 20 02 02 97 9.8 81 12.1 6.9 2.4 8.5 8.4 9.1 9.1 8.4 8.1 10 0 0.0 0.1 000000 1012.5 0.0 0.0 1.2
25 7 19 02 02 97 8.2 92 12.4 3.2 0.4 6.7 6.8 8.2 8.8 8.4 8.1 00 0 2.0 1.1 000000 1000.0 2.0 0.0 0.9
26 8 22 02 21 96 6.6 91 12.6 5.4 4.8 7.5 7.6 8.5 8.9 8.5 8.3 10 0 0.0 4.1 000000 1002.0 0.0 0.0 1.1
27 0 00 00 02 97 7.7 76 10.2 -1.0 -3.2 5.0 4.8 6.9 8.2 8.3 8.3 10 0 0.0 10.4 000000 1008.0 0.0 2.5 1.7
28 0 22 02 02 97 6.2 96 15.7 -0.8 -2.8 4.1 4.6 7.0 8.4 8.2 8.3 00 0 tr 10.7 000000 1017.0 0.0 1.3 3.2
29 8 23 09 52 97 11.6 90 14.7 6.2 8.0 9.2 8.9 9.1 8.8 8.4 8.2 00 0 1.0 0.5 000000 1014.5 1.7 0.0 0.8
30 8 19 02 02 96 10.2 96 13.2 9.5 8.0 9.4 9.4 9.8 9.3 8.6 8.4 10 0 1.4 0.0 000000 1017.0 2.4 0.0 0.6
31 7 13 02 02 97 13.2 92 19.4 9.9 6.7 9.3 9.4 9.8 9.6 8.8 8.5 10 0 0.0 5.8 000000 1019.0 0.0 0.0 1.6
-----------------------------------------------------------------------------------------------------------------
Mean
5.5 3.3 7.7 87 12.4 4.2 1.8 6.2 6.3 7.3 7.8 7.5 7.6 1012.8
Total 22.2 112.1 36.3 15.6 40.0
1961-1990 Climatological
Mean6.0 6.3 83 10.7 2.7 0.0 4.6 4.9 5.8 5.9 6.2 6.4 51.6 106.1 1015.0 57
-----------------------------------------------------------------------------------------------------------------
Snow days 1; mean 2.7; 50% snow cover at 09h days 0; mean 0.6;
Hail days 0; mean 0.5; Ice pellets days 0; mean 0.5;
Thunder days 0; mean 0.5; Fog at 09h days 0; mean 0.8;
Gale days 0; mean 0.4;
Air frost days 5; mean 6.4; Days with 0.2mm rain days 13; mean 15.3*
Grass minimum frost days 10; mean 15.5; Days with 1.0mm rain days 9; mean 10.6*
Soil frost days 3 Days with 5.0mm rain days 0; mean 3.9*
Concrete frost days 3 Days with no sun days 2; mean 6.4
Air pressure: max - 1032.0mb/16th, min - 984.0mb/3rd
Key
DD: date
07GMT observations...
N cloud cover (oktas, 9=obscured); dd wind direction (degrees/10); ff wind speed (knots);
VV visibility (00-50 metres/100, 94 very poor, 95 poor, 96 moderate, 97 good);
Soil temperatures are for 07GMT beneath a bare soil surface (degC);
Earth temperatures are for 07GMT beneath a grass surface (degC); SS snow depth (cm)
ww present weather code (02 sky not changing, 03 cloud increasing, 21 recent rain,
50 intermittent light drizzle, 52 intermittent moderate drizzle, 61 continuous light rain);
09GMT observations...
Temp temperature (degC); RH relative humidity (%); SS snow depth (cm);
Press air pressure (mb); E state of ground (00 dry, 10 moist, 20 wet, 40 frozen, 50 glaze;
24 hour readings...
Max maximum temperature (degC) beginning 09GMT, Min minimum temperature (degC) ending 09GMT;
Gmin grass minimum temperature (degC) ending 09GMT; Pch Evap Piche evaporation (ml) beginning O9GMT;
Rain rainfall beginning 09GMT (mm); Sun sunshine (hours) sunrise-sunset;
Rain hrs hours of rainfall (>0.1mm/hr) 09-09GMT; Fr. hrs hours of air frost (00-24GMT)
Days with...
S snow/sleet falling; L 50% snow cover at 09GMT; H>4 hail falling;
H<5 ice pellets, snow grains, snow pellets falling; T thunder heard;
G gale; F fog at 09GMT;
* Averages for Hurley (4km away)
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MAIDENHEAD METEOROLOGICAL OBSERVATIONS FOR APRIL 1999
-09GMT- --Temperature- --Soil temps-- -Earth temps-- Rain Fr. Pch
DD N dd ff ww VV Temp RH Max Min Gmin 5cm 10cm 20cm 30cm 50cm 1m E SS Rain Sun SLHTGF Press hrs hrs Evap
-----------------------------------------------------------------------------------------------------------------
01 2 14 02 02 96 14.0 63 21.1 8.2 4.0 9.3 8.6 9.9 10.0 9.2 8.6 00 0 0.0 9.8 000000 1013.5 0.0 0.0 3.0
02 8 20 02 03 97 12.1 75 17.5 9.3 6.2 10.0 10.0 10.7 10.6 9.6 8.8 00 0 tr 4.6 000000 1015.0 0.0 0.0 1.6
03 8 00 00 20 96 10.1 88 13.0 4.5 1.4 9.6 9.4 10.1 10.6 10.0 9.0 00 0 0.1 0.0 000000 1018.5 0.1 0.0 0.4
04 7 00 00 02 96 11.5 88 17.4 8.9 6.0 10.0 10.0 10.5 10.5 9.7 9.1 00 0 tr 0.2 000000 1026.5 0.0 0.0 1.1
05 8 11 05 02 96 13.4 87 15.8 11.5 10.6 12.1 11.7 11.6 10.9 10.2 9.2 00 0 0.1 0.8 000000 1025.5 0.2 0.0 1.2
06 8 22 12 02 97 13.0 88 18.6 10.7 8.9 11.3 11.2 11.4 10.0 10.3 9.4 00 0 0.4 3.9 000000 1020.0 0.2 0.0 2.1
07 7 21 09 02 97 10.2 71 14.0 7.2 4.2 9.4 9.5 10.9 11.2 10.5 9.6 10 0 tr 1.2 000000 1021.0 0.0 0.0 1.6
08 1 30 02 02 97 9.7 83 17.7 4.3 0.9 7.7 8.2 9.9 10.6 10.4 9.7 00 0 0.0 5.5 000000 1027.5 0.0 0.0 1.4
09 8 18 02 02 97 12.3 88 16.5 9.7 6.4 11.6 11.5 11.7 11.3 10.5 9.8 00 0 0.0 2.0 000000 1026.0 0.0 0.0 1.1
10 8 22 09 03 97 11.9 87 16.7 9.9 5.4 10.9 10.7 11.1 11.2 10.7 9.9 00 0 tr 0.9 000000 1019.0 0.0 0.0 1.6
11 0 35 02 02 97 12.1 64 15.6 4.6 2.0 7.5 7.9 9.7 10.7 10.6 10.0 00 0 5.1 7.9 000000 1022.0 3.5 0.0 2.2
12 6 26 09 02 97 8.9 71 13.4 7.5 5.5 9.0 9.4 10.8 11.0 10.5 10.0 10 0 3.7 3.0 004100 997.5 2.0 0.0 1.2
13 1 32 05 02 97 9.9 57 10.0 4.6 2.9 7.3 7.9 9.7 10.7 10.4 10.0 10 0 1.2 8.0 105000 1007.0 0.8 0.0 1.5
14 7 02 02 02 97 5.5 58 9.4 -1.8 -2.1 4.5 5.1 7.9 9.8 10.0 10.0 10 0 0.0 6.6 000000 999.5 0.0 1.5 2.0
15 1 04 02 02 97 4.0 70 11.9 -1.7 -2.2 4.1 4.4 7.3 9.2 9.5 9.9 10 0 0.2 9.6 004000 1003.0 0.3 2.0 1.9
16 9 00 00 43 03 6.6 77 11.2 -0.3 -0.9 5.5 6.0 8.0 9.4 9.4 9.7 10 0 tr 4.3 000000 1005.5 0.0 0.8 1.3
17 8 00 00 43 05 7.3 79 13.4 0.1 -1.7 6.1 5.9 7.7 8.9 9.2 9.6 10 0 tr 5.0 000100 1012.0 0.0 0.0 1.8
18 6 32 02 28 94 8.2 74 12.7 1.3 -1.0 6.2 6.3 8.1 9.1 9.2 9.5 00 0 0.2 5.0 000000 1016.5 0.2 0.0 1.2
19 7 05 02 02 95 5.6 90 12.1 -0.2 -2.1 5.2 5.8 8.0 9.3 9.3 9.4 00 0 1.8 3.4 000000 1020.0 4.4 0.4 1.9
20 8 15 05 60 95 8.5 97 12.2 5.6 2.0 8.1 8.1 9.0 9.1 9.2 9.4 10 0 9.6 0.0 000000 1003.5 8.1 0.0 0.5
21 7 22 09 25 97 12.0 72 14.8 8.5 4.6 9.1 9.1 9.4 9.4 9.1 9.3 10 0 2.2 2.6 000000 996.5 1.8 0.0 1.9
22 7 23 13 02 97 11.0 73 13.7 9.7 8.1 9.9 9.6 10.2 10.0 9.4 9.3 10 0 6.4 3.5 004100 1004.5 3.2 0.0 1.3
23 8 18 05 02 97 9.5 90 12.5 6.9 3.5 9.4 9.3 10.0 10.2 9.5 9.4 10 0 3.9 0.0 000000 1008.0 5.9 0.0 0.4
24 8 17 02 02 97 11.0 87 16.0 8.2 5.0 9.8 9.8 10.3 10.1 9.6 9.5 10 0 0.0 2.4 000000 1015.0 0.0 0.0 1.7
25 8 18 02 03 97 12.6 70 17.1 4.6 2.6 9.2 9.3 10.2 10.5 9.9 9.5 10 0 7.7 2.9 000000 1015.5 12.0 0.0 1.6
26 8 15 02 21 94 12.0 87 17.1 9.9 9.4 10.7 10.8 11.2 11.0 10.3 9.7 10 0 0.5 0.8 000000 1015.0 1.3 0.0 1.2
27 8 09 09 02 97 14.5 74 19.0 10.1 9.9 11.2 11.1 11.5 11.2 10.4 9.8 10 0 0.0 10.0 000000 1025.0 0.0 0.0 3.6
28 0 09 09 02 97 13.3 65 19.7 7.7 5.2 9.2 9.6 11.1 11.5 10.7 9.9 10 0 tr 13.3 000000 1028.0 0.0 0.0 3.7
29 8 04 09 50 96 9.8 83 17.5 7.2 5.0 10.1 10.6 11.7 11.9 11.1 10.1 00 0 0.0 10.0 000000 1022.5 0.0 0.0 3.1
30 0 36 05 02 97 11.0 71 21.6 4.6 1.9 8.8 9.4 11.1 11.8 11.2 10.2 00 0 0.0 13.7 000000 1018.5 0.0 0.0 2.6
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Mean
5.9 4.6 10.4 78 15.3 6.0 3.7 8.8 8.9 10.0 10.4 10.0 9.6 1014.9
Total 43.1 140.9 44.0 4.7 51.7
1961-1990 Climatological
Mean5.1 6.1 77 13.5 4.8 2.0 7.2 7.7 8.2 8.7 8.3 8.0 45.9 140.9 1015.2 45
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Snow days 1; mean 1.0; 50% snow cover at 09h days 0; mean 0.1;
Hail days 1; mean 0.3; Ice pellets days 3; mean 0.3;
Thunder days 3; mean 0.6; Fog at 09h days 0; mean 0.1;
Gale days 0; mean 0.0;
Air frost days 4; mean 2.1; Days with 0.2mm rain days 13; mean 14.1*
Grass minimum frost days 6; mean 9.2; Days with 1.0mm rain days 9; mean 10.1*
Soil frost days 0 Days with 5.0mm rain days 4; mean 3.4*
Concrete frost days 2 Days with no sun days 3; mean 3.4
Air pressure: max - 1028.5mb/28th min - 994.0mb/12th
Key
DD: date
07GMT observations...
N cloud cover (oktas, 9=obscured); dd wind direction (degrees/10); ff wind speed (knots);
VV visibility (00-50 metres/100, 94 very poor, 95 poor, 96 moderate, 97 good);
Soil temperatures are for 07GMT beneath a bare soil surface (degC);
Earth temperatures are for 07GMT beneath a grass surface (degC); SS snow depth (cm)
ww present weather code (02 sky not changing, 03 cloud increasing, 20 recent drizzle, 21 recent rain,
25 recent rain shower, 28 recent fog, 43 fog, 50 intermittent light drizzle, 60 intermittent light rain);
09GMT observations...
Temp temperature (degC); RH relative humidity (%); SS snow depth (cm);
Press air pressure (mb); E state of ground (00 dry, 10 moist, 20 wet, 40 frozen, 50 glaze);
24 hour readings...
Max maximum temperature (degC) beginning 09GMT, Min minimum temperature (degC) ending 09GMT;
Gmin grass minimum temperature (degC) ending 09GMT; Pch Evap Piche evaporation (ml) beginning O9GMT;
Rain rainfall beginning 09GMT (mm); Sun sunshine (hours) sunrise-sunset;
Rain hrs hours of rainfall (>0.1mm/hr) 09-09GMT; Fr. hrs hours of air frost (00-24GMT)
Days with...
S snow/sleet falling; L 50% snow cover at 09GMT; H>4 hail falling;
H<5 ice pellets, snow grains, snow pellets falling; T thunder heard;
G gale; F fog at 09GMT;
* Averages for Hurley (4km away)
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MAIDENHEAD METEOROLOGICAL OBSERVATIONS FOR MAY 1999
-09GMT- --Temperature- --Soil temps-- -Earth temps-- Rain Fr. Pch
DD N dd ff ww VV Temp RH Max Min Gmin 5cm 10cm 20cm 30cm 50cm 1m E SS Rain Sun SLHTGF Press hrs hrs Evap
-----------------------------------------------------------------------------------------------------------------
01 0 36 02 05 96 15.0 64 21.4 6.1 3.9 10.7 11.1 12.4 12.7 11.4 10.4 00 0 0.0 7.9 000000 1019.0 0.0 0.0 3.0
02 7 02 02 02 97 15.2 66 21.6 10.8 10.2 13.1 13.1 13.7 13.2 12.2 10.6 00 0 0.0 8.9 000000 1022.5 0.0 0.0 3.0
03 0 06 05 02 97 15.4 73 23.3 7.8 5.5 12.4 12.7 13.8 13.8 12.5 10.8 00 0 0.0 9.3 000000 1022.0 0.0 0.0 3.6
04 8 09 02 02 97 14.1 72 19.2 10.1 7.2 12.7 13.2 14.4 14.2 12.8 11.1 00 0 0.0 4.4 000000 1018.5 0.0 0.0 3.8
05 4 34 02 02 97 15.0 70 19.1 9.1 6.6 12.2 12.7 14.9 13.9 12.9 11.4 00 0 5.7 4.8 000000 1012.0 4.5 0.0 1.9
06 8 08 02 41 09 14.0 87 17.0 11.0 8.5 13.3 13.5 14.3 13.9 12.9 11.5 10 0 0.0 3.3 000000 1014.0 0.0 0.0 1.7
07 7 17 05 03 97 13.9 81 15.7 6.7 4.1 11.0 11.5 13.0 13.5 12.7 11.6 10 0 8.4 0.0 000000 1011.0 5.6 0.0 1.5
08 7 19 02 02 97 14.1 77 16.0 8.7 6.4 11.8 12.0 13.0 13.2 12.5 11.6 10 0 2.0 2.0 000000 1010.5 1.5 0.0 1.8
09 8 22 09 02 97 14.8 75 20.8 12.0 10.0 11.5 12.1 12.8 13.4 12.6 11.6 10 0 0.8 5.0 000000 1016.0 0.2 0.0 2.9
10 1 22 09 02 97 15.5 66 17.1 10.5 9.3 12.0 12.5 13.2 13.8 12.8 11.7 10 0 1.1 7.1 000000 1010.5 0.2 0.0 1.8
11 0 18 09 02 97 14.5 73 18.5 11.9 7.8 13.0 12.9 13.9 14.0 12.9 11.9 10 0 0.0 8.6 000000 1011.0 0.0 0.0 2.6
12 6 22 09 02 97 15.0 67 16.9 11.3 7.6 12.8 12.9 13.7 14.0 13.0 12.0 10 0 0.4 3.3 000000 1010.5 0.6 0.0 1.7
13 7 21 02 02 97 13.5 77 16.3 9.8 8.4 12.8 12.9 13.9 14.0 13.3 12.1 10 0 7.2 0.5 000000 1011.0 3.2 0.0 0.8
14 7 27 02 25 97 13.0 85 16.9 10.1 8.0 12.8 12.8 13.6 13.8 13.2 12.1 10 0 4.4 3.0 004000 1011.0 1.3 0.0 1.1
15 5 36 02 02 97 13.2 80 14.9 9.7 8.0 12.9 13.1 13.9 13.9 13.1 12.1 10 0 0.0 1.9 000000 1019.0 0.0 0.0 1.6
16 7 06 02 03 97 14.5 67 16.6 6.1 4.0 12.8 12.2 12.9 13.4 13.1 12.2 10 0 0.0 4.4 000000 1024.0 0.0 0.0 2.6
17 6 07 09 02 97 11.1 80 15.5 7.4 3.9 10.5 10.8 12.5 13.3 12.9 12.2 10 0 tr 6.1 000000 1022.0 0.0 0.0 3.5
18 8 07 17 60 97 12.0 76 16.4 10.7 8.9 11.6 11.7 12.8 13.0 12.7 12.2 00 0 0.2 0.0 000000 1014.5 0.2 0.0 1.3
19 6 09 02 02 96 16.4 82 23.8 8.7 6.4 11.6 11.7 12.7 12.8 12.4 12.1 10 0 20.6 7.6 006100 1013.0 0.8 0.0 2.2
20 7 31 05 02 96 14.6 81 22.5 10.0 8.2 13.1 13.1 14.0 14.0 13.0 12.1 10 0 0.0 8.1 000000 1014.0 0.0 0.0 2.4
21 3 27 02 02 97 15.1 72 17.6 9.8 7.7 13.0 13.7 15.0 14.8 13.5 12.2 10 0 0.0 3.7 000000 1016.0 0.0 0.0 2.2
22 7 30 09 02 97 13.4 60 17.7 8.0 6.2 11.9 12.4 13.9 14.4 13.6 12.5 10 0 0.0 11.0 000000 1019.0 0.0 0.0 2.6
23 8 20 09 02 97 14.7 83 18.9 10.2 7.8 14.4 14.2 14.6 14.6 13.7 12.6 00 0 0.0 1.3 000000 1020.5 0.0 0.0 1.9
24 8 27 05 02 97 14.6 77 18.0 12.2 11.5 13.9 14.2 14.9 14.6 13.7 12.7 00 0 0.5 0.1 000000 1020.0 0.2 0.0 1.4
25 2 19 02 02 97 14.3 56 18.8 7.6 4.8 12.1 12.7 14.0 14.4 13.7 12.8 00 0 0.0 14.2 000000 1022.0 0.0 0.0 2.6
26 5 20 02 02 97 14.7 82 20.9 6.8 4.3 12.2 12.8 14.5 14.9 13.9 12.9 00 0 0.0 4.2 000000 1020.0 0.0 0.0 2.2
27 1 18 05 02 97 20.6 65 26.5 9.7 7.4 14.4 14.8 15.6 15.5 14.3 12.9 00 0 0.0 11.6 000000 1017.5 0.0 0.0 5.0
28 8 21 05 02 97 18.0 85 22.2 15.8 14.5 17.1 17.3 17.7 16.5 14.9 13.1 00 0 0.0 7.6 000000 1018.0 0.0 0.0 3.0
29 0 24 05 02 97 20.7 73 25.7 10.5 8.5 15.8 15.8 16.7 16.2 15.2 13.4 00 0 4.3 9.4 000100 1018.0 0.3 0.0 3.2
30 8 36 09 03 97 15.0 82 15.3 14.0 12.9 16.1 16.4 17.2 16.8 15.5 13.5 10 0 0.1 0.0 000000 1017.5 0.1 0.0 1.0
31 8 04 02 02 97 11.4 82 17.3 10.1 9.6 13.6 13.8 14.9 15.4 15.0 13.7 10 0 0.0 0.1 000000 1025.5 0.0 0.0 1.6
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Mean
5.4 5.0 14.8 75 19.0 9.8 7.7 12.9 13.1 14.1 14.2 13.3 12.1 1016.8
Total 55.7 159.4 18.7 0.0 71.5
1961-1990 Climatological
Mean4.9 6.4 73 17.1 7.9 5.6 10.7 10.7 12.1 12.2 11.2 10.1 54.1 187.3 1015.2 46
-----------------------------------------------------------------------------------------------------------------
Snow days 0; mean 0.1; 50% snow cover at 09h days 0; mean 0.0;
Hail days 0; mean 0.3; Ice pellets days 1; mean 0.1;
Thunder days 2; mean 1.8; Fog at 09h days 0; mean 0.1;
Gale days 0; mean 0.0;
Air frost days 0; mean 0.2; Days with 0.2mm rain days 12; mean 13.7*
Grass minimum frost days 0; mean 2.0; Days with 1.0mm rain days 8; mean 10.3*
Soil frost days 0 Days with 5.0mm rain days 4; mean 3.6*
Concrete frost days 0 Days with no sun days 3; mean 2.3
Air pressure: max - 1025.5mb/31st min - 1007.0mb/7th
Key
DD: date
07GMT observations...
N cloud cover (oktas, 9=obscured); dd wind direction (degrees/10); ff wind speed (knots);
VV visibility (00-50 metres/100, 94 very poor, 95 poor, 96 moderate, 97 good);
Soil temperatures are for 07GMT beneath a bare soil surface (degC);
Earth temperatures are for 07GMT beneath a grass surface (degC); SS snow depth (cm)
ww present weather code (02 sky not changing, 03 cloud increasing, 05 haze,
25 recent rain shower, 41 fog patches, 60 intermittent light rain);
09GMT observations...
Temp temperature (degC); RH relative humidity (%); SS snow depth (cm);
Press air pressure (mb); E state of ground (00 dry, 10 moist, 20 wet, 90 cracked);
24 hour readings...
Max maximum temperature (degC) beginning 09GMT, Min minimum temperature (degC) ending 09GMT;
Gmin grass minimum temperature (degC) ending 09GMT; Pch Evap Piche evaporation (ml) beginning O9GMT;
Rain rainfall beginning 09GMT (mm); Sun sunshine (hours) sunrise-sunset;
Rain hrs hours of rainfall (>0.1mm/hr) 09-09GMT; Fr. hrs hours of air frost (00-24GMT)
Days with...
S snow/sleet falling; L 50% snow cover at 09GMT; H>4 hail falling;
H<5 ice pellets, snow grains, snow pellets falling; T thunder heard;
G gale; F fog at 09GMT;
* Averages for Hurley (4km away)
May 1999 was much milder than average, but cooler than in 1998.
A thunderstorm on the 19th gave 20mm of precipitation in 20 minutes, with hail 1cm in diameter.
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MAIDENHEAD METEOROLOGICAL OBSERVATIONS FOR JUNE 1999
-09GMT- --Temperature- --Soil temps-- -Earth temps-- Rain Fr. Pch
DD N dd ff ww VV Temp RH Max Min Gmin 5cm 10cm 20cm 30cm 50cm 1m E SS Rain Sun SLHTGF Press hrs hrs Evap
-----------------------------------------------------------------------------------------------------------------
01 3 08 02 01 97 17.3 71 23.4 12.1 11.6 14.2 14.6 15.3 15.2 14.7 13.7 10 0 30.5 11.4 000000 1022.5 6.9 0.0 2.4
02 8 09 02 44 08 16.0 94 19.5 13.5 11.7 15.4 15.6 16.7 16.4 15.2 13.8 10 0 5.7 0.9 000100 1005.5 1.8 0.0 1.0
03 8 25 09 02 97 15.2 86 18.5 11.7 10.1 15.0 15.2 15.7 15.9 15.1 13.9 10 0 3.4 1.9 000000 1008.0 4.9 0.0 1.5
04 8 22 05 25 97 13.6 88 17.3 10.7 9.5 14.2 14.5 15.4 15.5 14.9 13.9 10 0 1.3 2.3 000000 1005.5 0.8 0.0 1.8
05 2 27 05 02 97 13.8 76 17.8 9.1 7.8 13.0 13.5 14.7 15.3 14.8 13.9 10 0 9.7 7.8 000000 1003.0 3.7 0.0 1.5
06 8 32 09 21 97 13.8 80 19.4 9.2 7.7 13.8 13.9 14.8 15.2 14.7 13.9 10 0 0.9 8.4 000000 1003.5 2.2 0.0 1.9
07 8 27 02 21 97 15.1 90 18.8 9.9 7.2 14.0 14.2 15.0 15.4 14.8 13.9 10 0 0.1 5.3 000000 1010.0 0.2 0.0 1.6
08 0 29 09 02 97 14.5 77 19.3 5.6 3.6 12.1 12.7 14.5 15.4 14.7 13.9 10 0 0.0 11.4 000000 1020.0 0.0 0.0 2.7
09 0 33 02 02 97 15.2 76 19.5 5.6 3.8 12.7 13.1 14.9 15.5 14.9 13.9 10 0 0.0 10.1 000000 1025.5 0.0 0.0 2.3
10 7 30 05 03 97 13.7 80 18.0 6.2 5.0 12.8 13.1 14.7 15.3 14.9 14.0 10 0 0.0 1.0 000000 1027.5 0.0 0.0 1.9
11 8 30 09 02 97 13.1 81 17.1 12.0 11.4 14.4 14.6 15.3 15.2 14.7 14.0 00 0 0.0 0.0 000000 1027.5 0.0 0.0 1.7
12 8 24 02 02 97 14.1 83 16.4 12.7 12.1 14.8 14.9 15.4 15.1 14.5 13.9 00 0 0.7 0.0 000000 1023.0 1.3 0.0 1.1
13 1 29 02 02 97 15.0 75 20.3 8.5 7.2 14.1 13.9 14.5 14.9 14.5 13.9 10 0 0.0 8.3 000000 1024.0 0.0 0.0 2.0
14 1 00 00 02 97 18.0 84 23.0 10.2 8.9 14.4 14.8 15.9 15.7 14.6 13.9 00 0 tr 6.6 000000 1026.0 0.0 0.0 2.1
15 4 00 00 02 97 18.3 80 25.5 10.2 9.0 14.9 15.3 16.5 16.3 15.3 13.8 00 0 0.0 13.4 000000 1027.5 0.0 0.0 2.6
16 4 00 00 02 97 19.4 71 26.2 11.2 9.3 16.2 16.7 17.9 17.4 16.0 14.1 00 0 0.0 14.2 000000 1025.0 0.0 0.0 3.4
17 6 33 02 03 97 17.0 73 21.2 12.2 10.0 16.7 17.2 18.5 18.1 16.6 14.4 00 0 0.0 5.2 000000 1023.5 0.0 0.0 2.7
18 3 29 02 02 97 16.8 62 24.1 8.9 7.4 14.9 15.6 17.1 17.4 16.6 14.7 00 0 0.0 13.6 000000 1027.5 0.0 0.0 2.9
19 1 24 02 02 97 18.3 79 20.3 11.0 9.4 16.4 16.8 18.0 17.9 16.8 14.9 00 0 3.9 5.6 000000 1023.5 4.0 0.0 1.9
20 8 22 02 51 95 16.6 89 20.1 14.5 14.1 17.2 19.1 18.0 17.6 16.7 15.0 10 0 0.0 10.0 000000 1012.0 0.0 0.0 2.7
21 4 33 09 02 97 12.5 63 17.4 9.1 7.1 14.6 15.3 16.9 17.5 16.9 15.1 00 0 0.0 4.8 000000 1020.0 0.0 0.0 2.5
22 4 27 02 02 97 14.4 58 18.6 5.8 4.3 12.8 13.7 15.7 16.4 16.3 15.1 00 0 0.0 6.9 000000 1024.5 0.0 0.0 2.5
23 6 29 02 02 97 15.6 67 23.6 12.0 10.7 15.4 15.7 16.8 16.7 16.2 15.1 00 0 0.0 6.7 000000 1024.0 0.0 0.0 2.8
24 7 23 02 02 97 18.9 60 22.7 10.2 8.6 16.2 16.5 17.5 17.5 16.6 15.1 00 0 0.0 5.1 000000 1027.0 0.0 0.0 2.8
25 1 07 05 02 97 17.4 42 23.6 10.8 8.9 15.8 16.3 17.6 17.5 16.5 15.1 00 0 0.0 14.5 000000 1024.5 0.0 0.0 4.2
26 6 10 02 03 97 21.3 49 27.0 10.3 8.1 16.1 16.4 17.9 17.8 17.0 15.4 00 0 0.1 9.0 000000 1010.5 0.3 0.0 3.5
27 7 18 09 02 97 17.1 77 18.5 13.6 13.0 16.4 16.5 17.5 17.5 17.0 15.5 00 0 0.4 4.5 000000 1000.5 0.4 0.0 1.6
28 6 22 09 02 97 15.9 70 19.5 9.5 7.4 14.7 15.0 16.5 17.1 17.0 15.6 00 0 23.5 5.5 000000 1008.5 14.8 0.0 2.3
29 8 29 05 61 94 14.5 97 17.7 13.4 13.0 16.2 16.4 17.2 17.2 16.7 15.5 10 0 7.5 0.0 000000 1009.5 7.7 0.0 0.1
30 0 27 02 03 97 15.5 70 20.5 10.1 9.0 15.4 15.6 16.9 16.9 16.3 15.5 10 0 0.9 8.2 000000 1019.0 0.9 0.0 1.9
-----------------------------------------------------------------------------------------------------------------
Mean
4.8 3.9 15.9 75 20.5 10.3 8.9 14.8 15.2 16.3 16.4 15.7 14.5 1018.0
Total 88.6 202.6 49.9 0.0 65.9
Climatological
Mean5.3 5.6 72 20.0 10.7 9.0 14.3 14.5 15.6 15.2 14.1 12.5 52.6 191.8 1017.0 41
-----------------------------------------------------------------------------------------------------------------
Snow days 0; mean 0.0; 50% snow cover at 09h days 0; mean 0.0;
Hail days 0; mean 0.1; Ice pellets days 0; mean 0.0;
Thunder days 1; mean 2.3; Fog at 09h days 0; mean 0.1;
Gale days 0; mean 0.0;
Air frost days 0; mean 0.0; Days with 0.2mm rain days 12; mean 11.5*
Grass minimum frost days 0; mean 0.0; Days with 1.0mm rain days 8; mean 8.2*
Soil frost days 0 Days with 5.0mm rain days 5; mean 3.6*
Concrete frost days 0 Days with no sun days 3; mean 2.1
Air pressure: max - 1027.5mb/various dates min - 999.0mb/6th
Key
DD: date
07GMT observations...
N cloud cover (oktas, 9=obscured); dd wind direction (degrees/10); ff wind speed (knots);
VV visibility (00-50 metres/100, 94 very poor, 95 poor, 96 moderate, 97 good);
Soil temperatures are for 07GMT beneath a bare soil surface (degC);
Earth temperatures are for 07GMT beneath a grass surface (degC); SS snow depth (cm)
ww present weather code (01 cloud decreasing, 02 sky not changing, 03 cloud increasing, 21 recent rain,
25 recent rain showers, 44 fog, 51 continuous light drizzle, 61 continuous light rain)
09GMT observations...
Temp temperature (degC); RH relative humidity (%);
Press air pressure (mb); E state of ground (00 dry, 10 moist, 20 wet, 90 cracked);
24 hour readings...
Max maximum temperature (degC) beginning 09GMT, Min minimum temperature (degC) ending 09GMT;
Gmin grass minimum temperature (degC) ending 09GMT; Pch Evap Piche evaporation (ml) beginning O9GMT;
Rain rainfall beginning 09GMT (mm); Sun sunshine (hours) sunrise-sunset;
Rain hrs hours of rainfall (>0.1mm/hr) 09-09GMT; Fr. hrs hours of air frost (00-24GMT)
Days with...
S snow/sleet falling; L 50% snow cover at 09GMT; H>4 hail falling;
H<5 ice pellets, snow grains, snow pellets falling; T thunder heard;
G gale; F fog at 09GMT;
* Averages for Hurley (4km away)
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MAIDENHEAD METEOROLOGICAL OBSERVATIONS FOR JULY 1999
-09GMT- --Temperature- --Soil temps-- -Earth temps-- Rain Fr. Pch
DD N dd ff ww VV Temp RH Max Min Gmin 5cm 10cm 20cm 30cm 50cm 1m E SS Rain Sun SLHTGF Press hrs hrs Evap
-----------------------------------------------------------------------------------------------------------------
01 8 29 05 02 97 17.4 80 21.1 13.2 8.9 16.3 16.4 17.4 17.1 16.4 15.4 10 0 0.5 0.9 000000 1016.5 0.5 0.0 1.1
02 8 18 02 10 94 18.5 80 26.3 13.3 11.9 16.6 16.8 17.4 17.3 16.4 15.4 10 0 15.3 10.0 000000 1017.0 1.5 0.0 2.3
03 7 31 05 02 97 19.2 76 23.4 18.0 15.0 19.4 19.4 19.4 18.6 17.1 15.5 10 0 0.0 5.0 000100 1007.5 0.0 0.0 1.9
04 7 18 05 02 96 18.5 74 23.0 14.3 12.8 18.0 18.8 19.1 18.4 17.2 15.7 10 0 1.2 1.8 000000 1010.5 0.3 0.0 1.7
05 6 09 02 03 97 18.7 78 23.7 13.9 13.0 17.3 17.7 18.5 18.2 17.2 15.9 10 0 4.7 3.8 000100 1009.5 1.8 0.0 1.0
06 5 00 00 28 94 18.8 75 26.0 12.6 11.9 16.9 17.3 18.2 18.2 17.4 16.0 10 0 tr 7.9 000000 1015.5 0.0 0.0 2.3
07 7 23 02 02 97 19.4 75 24.9 15.2 13.5 18.4 18.6 19.3 18.9 17.7 16.0 10 0 0.0 5.0 000000 1023.0 0.0 0.0 2.1
08 7 09 02 03 97 23.0 61 27.3 14.4 13.1 18.4 18.8 19.5 19.3 18.0 16.1 10 0 0.0 8.9 000000 1030.0 0.0 0.0 3.1
09 8 04 02 02 97 20.8 70 24.6 18.6 16.5 19.9 19.9 20.5 19.7 18.4 16.4 00 0 0.0 1.9 000000 1029.0 0.0 0.0 2.8
10 0 07 05 02 97 20.8 69 26.4 13.4 11.3 17.7 17.9 19.4 19.3 18.3 16.6 00 0 0.0 12.6 000000 1025.5 0.0 0.0 3.9
11 3 04 09 02 97 21.4 68 27.4 14.3 12.5 18.3 18.4 19.4 19.5 18.5 16.7 00 0 0.0 13.9 000000 1023.0 0.0 0.0 3.5
12 7 02 13 02 97 20.9 69 24.7 14.8 12.5 18.4 18.8 19.9 19.6 18.6 16.8 00 0 0.0 11.9 000000 1019.0 0.0 0.0 2.8
13 0 31 02 02 97 18.8 60 25.9 11.6 9.9 17.1 17.1 19.4 19.5 18.7 16.9 00 0 tr 7.5 000000 1011.0 0.0 0.0 2.4
14 7 31 09 02 97 18.2 55 19.0 12.7 10.6 17.7 18.3 19.7 19.8 18.8 17.0 00 0 tr 3.1 000000 1010.0 0.0 0.0 2.0
15 7 24 02 02 96 17.3 71 21.5 9.3 7.1 15.6 16.4 17.9 18.5 18.3 17.1 00 0 0.0 7.4 000000 1014.0 0.0 0.0 2.7
16 7 25 02 02 97 18.7 65 21.5 11.0 9.6 16.7 17.2 18.6 18.6 18.2 17.0 00 0 0.0 2.0 000000 1019.0 0.0 0.0 1.9
17 7 29 05 02 97 18.8 59 25.6 15.8 13.6 18.6 18.4 19.0 18.4 18.1 16.9 00 0 0.0 11.7 000000 1018.5 0.0 0.0 3.0
18 1 03 02 02 97 21.5 67 27.6 11.0 9.4 17.0 17.4 18.9 19.1 18.5 16.9 00 0 0.0 14.3 000000 1016.5 0.0 0.0 3.2
19 7 20 02 02 97 22.5 55 24.4 15.1 13.2 19.1 19.4 20.2 19.8 19.0 17.0 00 0 1.2 5.5 000000 1011.0 2.2 0.0 2.5
20 7 22 05 02 97 21.1 73 23.4 16.4 13.4 19.2 19.4 20.3 19.8 19.2 17.2 10 0 tr 5.6 000000 1007.0 0.0 0.0 2.5
21 6 32 09 02 97 16.1 51 20.9 12.7 10.3 16.3 17.2 18.8 19.2 18.9 17.3 00 0 tr 5.3 000000 1014.5 0.0 0.0 3.4
22 8 33 09 02 97 15.5 63 16.9 11.2 8.9 16.4 16.9 18.4 18.4 18.5 17.3 90 0 0.0 0.1 000000 1019.5 0.0 0.0 1.3
23 7 26 02 02 97 16.0 65 25.4 7.8 6.4 14.8 15.1 16.9 17.5 17.9 17.2 90 0 0.0 12.6 000000 1026.5 0.0 0.0 2.9
24 0 00 00 02 97 24.3 61 29.0 13.2 11.4 17.2 17.3 18.6 18.5 18.2 17.1 90 0 0.0 13.8 000000 1024.5 0.0 0.0 2.8
25 6 08 05 03 97 24.1 63 28.9 14.5 12.5 19.0 19.0 19.9 19.5 18.9 17.1 90 0 0.0 9.5 000000 1020.5 0.0 0.0 4.0
26 8 04 13 02 97 15.7 79 23.0 14.9 14.0 18.7 19.4 20.6 20.0 19.2 17.2 90 0 tr 8.3 000000 1025.0 0.0 0.0 3.9
27 3 07 09 02 97 17.3 54 21.8 11.5 9.3 15.6 16.5 18.4 18.4 18.9 17.4 90 0 0.0 14.6 000000 1025.0 0.0 0.0 4.4
28 7 02 05 02 97 17.8 64 24.7 14.3 11.8 17.3 17.7 18.9 18.7 18.7 17.4 90 0 0.0 10.4 000000 1022.5 0.0 0.0 4.0
29 8 09 05 02 97 17.3 74 28.3 12.7 10.7 17.2 17.6 18.8 18.6 18.6 17.3 90 0 0.0 9.5 000000 1022.0 0.0 0.0 3.9
30 6 06 02 02 97 23.5 51 28.8 15.1 10.6 17.3 17.8 19.2 19.0 18.7 17.3 90 0 0.0 14.2 000000 1017.0 0.0 0.0 3.9
31 3 09 02 02 97 25.0 54 30.9 16.0 12.9 18.8 19.2 20.2 19.8 19.1 17.4 90 0 0.0 10.1 000100 1014.5 0.0 0.0 3.4
-----------------------------------------------------------------------------------------------------------------
Mean
5.7 4.6 19.6 66 24.7 13.6 11.6 17.6 17.9 19.1 18.9 18.2 16.7 1018.2
Total 22.9 249.1 6.3 0.0 86.6
1961-1990 Climatological
Mean5.2 5.5 73 22.1 12.5 10.8 16.0 16.4 17.3 17.3 16.3 15.1 46.7 191.2 1017.5 35
-----------------------------------------------------------------------------------------------------------------
Snow days 0; mean 0.0; 50% snow cover at 09h days 0; mean 0.0;
Hail days 0; mean 0.1; Ice pellets days 0; mean 0.0;
Thunder days 3; mean 1.9; Fog at 09h days 0; mean 0.1;
Gale days 0; mean 0.0;
Air frost days 0; mean 0.0 Days with 0.2mm rain days 5; mean 10.9*
Grass minimum frost days 0; mean 0.0 Days with 1.0mm rain days 4; mean 7.6*
Soil frost days 0 Days with 5.0mm rain days 1; mean 2.8*
Concrete frost days 0 Days with no sun days 0; mean 1.7
Air pressure: max - 1030.0mb/8th, min - 1005.5mb/3rd
Key
DD: date
07GMT observations...
N cloud cover (oktas, 9=obscured); dd wind direction (degrees/10); ff wind speed (knots);
VV visibility (00-50 metres/100, 94 very poor, 95 poor, 96 moderate, 97 good);
Soil temperatures are for 07GMT beneath a bare soil surface (degC);
Earth temperatures are for 07GMT beneath a grass surface (degC); SS snow depth (cm)
ww present weather code (02 sky not changing, 03 cloud increasing, 10 mist, 28 recent fog):
09GMT observations...
Temp temperature (degC); RH relative humidity (%); SS snow depth (cm);
Press air pressure (mb); E state of ground (00 dry, 10 moist, 20 wet, 90 cracked);
24 hour readings...
Max maximum temperature (degC) beginning 09GMT, Min minimum temperature (degC) ending 09GMT;
Gmin grass minimum temperature (degC) ending 09GMT; Pch Evap Piche evaporation (ml) beginning O9GMT;
Rain rainfall beginning 09GMT (mm); Sun sunshine (hours) sunrise-sunset;
Rain hrs hours of rainfall (>0.1mm/hr) 09-09GMT; Fr. hrs hours of air frost (00-24GMT)
Days with...
S snow/sleet falling; L 50% snow cover at 09GMT; H>4 hail falling;
H<5 ice pellets, snow grains, snow pellets falling; T thunder heard;
G gale; F fog at 09GMT;
* Averages for Hurley (4km away)
Warmest and driest July since 1995, sunniest since 1990.
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MAIDENHEAD METEOROLOGICAL OBSERVATIONS FOR AUGUST 1999
-09GMT- --Temperature- --Soil temps-- -Earth temps-- Rain Fr. Pch
DD N dd ff ww VV Temp RH Max Min Gmin 5cm 10cm 20cm 30cm 50cm 1m E SS Rain Sun SLHTGF Press hrs hrs Evap
-----------------------------------------------------------------------------------------------------------------
01 0 15 05 05 96 25.7 62 31.2 15.2 12.7 18.9 19.6 20.8 20.2 19.4 17.5 90 0 0.0 11.6 000100 1014.5 0.0 0.0 4.3
02 7 14 02 03 97 24.5 64 30.8 16.0 13.0 19.8 20.1 21.0 20.5 19.8 17.6 90 0 2.3 7.4 000000 1012.0 7.1 0.0 4.4
03 8 18 02 61 96 19.0 93 23.5 18.2 16.8 20.4 21.0 21.6 21.0 20.0 17.8 10 0 0.1 0.9 000000 1009.5 0.2 0.0 1.1
04 7 18 02 03 97 20.6 70 27.0 14.5 12.8 18.3 18.6 19.9 20.0 19.7 18.0 10 0 8.6 5.1 000000 1010.5 4.3 0.0 2.5
05 8 00 00 02 96 19.7 74 26.0 17.9 16.6 19.7 20.0 20.6 20.3 19.6 18.0 10 0 0.0 8.3 000000 1009.5 0.0 0.0 2.7
06 7 15 02 02 97 22.0 76 26.0 14.2 12.5 17.9 18.7 19.8 20.1 19.7 18.0 10 0 5.4 0.9 000000 1010.5 6.8 0.0 3.0
07 8 17 02 02 94 18.0 93 23.5 17.0 16.1 19.0 19.2 20.0 19.9 19.5 18.1 10 0 5.0 2.5 000000 1005.0 1.6 0.0 1.3
08 8 20 09 03 97 17.2 95 22.2 17.1 15.1 18.3 18.6 19.4 19.5 19.2 18.0 10 0 13.3 1.5 000000 998.0 4.7 0.0 0.6
09 7 18 02 02 97 18.7 86 21.0 15.4 14.0 18.0 18.0 18.0 19.2 19.1 18.0 10 0 48.8 1.0 000100 1001.0 14.0 0.0 0.5
10 8 36 09 21 97 14.0 93 18.1 13.6 12.0 16.2 16.0 17.6 18.8 18.8 18.0 10 0 0.0 0.3 000000 1011.0 0.0 0.0 0.9
11 5 36 02 02 97 17.0 65 19.9 10.7 8.9 15.5 15.0 16.5 17.8 18.6 17.9 10 0 0.2 4.5 000000 1022.0 0.2 0.0 1.3
12 7 13 05 01 97 16.5 70 20.4 12.7 11.0 16.5 16.0 17.5 18.0 18.3 17.8 10 0 0.5 2.0 000000 1022.5 0.7 0.0 1.7
13 7 18 02 21 97 17.8 82 21.0 12.5 10.0 16.0 15.5 18.0 18.2 18.0 17.6 10 0 0.4 1.2 000000 1016.0 1.7 0.0 2.0
14 1 23 09 02 97 18.5 60 21.6 14.8 13.4 16.8 17.2 18.9 18.4 17.8 17.4 10 0 tr 8.3 000000 1004.0 0.0 0.0 2.1
15 6 28 09 03 97 17.9 85 20.5 10.7 7.6 15.2 15.6 17.0 18.0 17.8 17.3 10 0 0.0 8.5 000000 1008.0 0.0 0.0 1.9
16 7 23 02 03 97 16.8 60 19.7 9.2 6.6 14.4 15.1 16.8 17.8 17.7 17.4 10 0 4.9 4.8 000100 1009.0 3.4 0.0 1.8
17 7 22 02 02 96 14.0 92 16.0 8.5 6.5 13.9 14.4 16.0 17.2 17.4 17.3 10 0 7.6 0.1 000100 1006.6 4.0 0.0 0.4
18 5 24 02 03 97 14.7 92 18.3 11.0 8.4 14.2 14.8 16.0 16.7 16.8 17.1 10 0 11.8 3.8 000100 996.0 3.8 0.0 0.5
19 3 23 05 02 97 17.5 70 20.9 12.5 9.6 14.6 14.9 15.7 16.5 16.5 16.9 10 0 0.0 10.2 000000 1009.5 0.0 0.0 1.9
20 0 00 00 02 97 16.0 71 21.6 8.1 6.0 13.4 14.2 15.9 16.9 16.7 16.7 10 0 tr 12.6 000000 1022.0 0.0 0.0 2.3
21 1 36 02 02 97 15.0 59 19.2 8.3 5.7 13.3 14.2 16.0 16.9 16.9 16.7 10 0 0.0 12.5 000000 1027.0 0.0 0.0 3.0
22 6 32 02 02 97 15.5 60 18.7 9.3 6.5 13.5 14.4 15.9 16.7 16.7 16.6 10 0 0.0 5.0 000000 1024.5 0.0 0.0 3.0
23 7 09 02 02 97 17.7 55 22.0 13.0 11.1 15.0 15.1 15.9 16.6 16.6 16.5 10 0 0.1 8.5 000000 1020.0 0.2 0.0 2.4
24 8 12 09 02 97 16.8 87 18.8 13.6 11.7 15.1 15.6 16.4 16.8 16.6 16.4 10 0 0.4 0.0 000000 1018.0 1.9 0.0 1.5
25 7 05 02 02 96 18.8 85 23.5 14.3 12.2 15.6 15.6 16.4 16.6 16.5 16.4 10 0 tr 1.1 000000 1014.0 0.0 0.0 0.7
26 8 22 02 60 97 19.8 68 24.2 16.6 13.9 17.2 17.3 16.5 17.1 16.4 16.3 10 0 0.0 6.2 000000 1011.0 0.0 0.0 2.5
27 7 23 05 02 97 17.7 77 22.4 11.6 9.5 15.0 15.5 16.0 17.1 16.6 16.4 00 0 0.0 6.0 000000 1020.0 0.0 0.0 1.9
28 1 27 02 02 96 18.9 73 24.5 9.8 7.0 14.0 14.5 15.5 16.9 16.7 16.6 00 0 0.0 12.0 000000 1025.5 0.0 0.0 2.3
29 1 00 00 02 97 19.9 63 23.7 10.4 7.5 14.5 15.0 16.0 17.4 17.0 16.5 00 0 0.0 7.5 000000 1023.0 0.0 0.0 2.2
30 7 36 05 02 97 17.8 73 23.4 12.0 10.0 14.5 15.0 15.5 17.9 17.1 16.6 90 0 0.0 10.5 000000 1021.5 0.0 0.0 2.3
31 7 27 02 02 97 18.0 70 23.0 11.7 8.0 14.0 14.5 15.0 17.8 17.4 16.8 90 0 0.0 3.0 000000 1015.0 0.0 0.0 1.6
-----------------------------------------------------------------------------------------------------------------
Mean
5.7 3.4 18.1 75 22.3 12.9 10.7 16.1 16.4 17.5 18.2 17.9 17.2 1013.4
Total 109.4 167.8 54.6 0.0 60.6
1961-1990 Climatological
Mean5.2 5.3 77 21.7 12.2 10.5 15.6 16.2 17.2 17.2 17.0 16.1 57.5 180.9 1016.4 39
-----------------------------------------------------------------------------------------------------------------
Snow days 0; mean 0.0; 50% snow cover at 09h days 0; mean 0.0;
Hail days 0; mean 0.0; Ice pellets days 0; mean 0.1;
Thunder days 5; mean 1.5; Fog at 09h days 0; mean 0.4;
Gale days 0; mean 0.0;
Air frost days 0; mean 0.0 Days with 0.2mm rain days 13; mean 12.4*
Grass minimum frost days 0; mean 0.0 Days with 1.0mm rain days 9; mean 8.6*
Soil frost days 0 Days with 5.0mm rain days 7; mean 3.4*
Concrete frost days 0 Days with no sun days 1; mean 2.2
Air pressure: max - 1027.0mb/21st, min - 996.0mb/18th
Key
DD: date
07GMT observations...
N cloud cover (oktas, 9=obscured); dd wind direction (degrees/10); ff wind speed (knots);
VV visibility (00-50 metres/100, 94 very poor, 95 poor, 96 moderate, 97 good);
Soil temperatures are for 07GMT beneath a bare soil surface (degC);
Earth temperatures are for 07GMT beneath a grass surface (degC); SS snow depth (cm)
ww present weather code (01 cloud decreasing, 02 sky not changing, 03 cloud increasing, 21 recent rain,
60 intermittent light rain, 61 continuous light rain);
09GMT observations...
Temp temperature (degC); RH relative humidity (%); SS snow depth (cm);
Press air pressure (mb); E state of ground (00 dry, 10 moist, 20 wet, 90 cracked);
24 hour readings...
Max maximum temperature (degC) beginning 09GMT, Min minimum temperature (degC) ending 09GMT;
Gmin grass minimum temperature (degC) ending 09GMT; Pch Evap Piche evaporation (ml) beginning O9GMT;
Rain rainfall beginning 09GMT (mm); Sun sunshine (hours) sunrise-sunset;
Rain hrs hours of rainfall (>0.1mm/hr) 09-09GMT; Fr. hrs hours of air frost (00-24GMT)
Days with...
S snow/sleet falling; L 50% snow cover at 09GMT; H>4 hail falling; F fog at 09GMT;
H<5 ice pellets, snow grains, snow pellets falling; T thunder heard; G gale;
* Averages for Hurley (4km away)
48.8mm on the 9th was the wettest day since September 1992.
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MAIDENHEAD METEOROLOGICAL OBSERVATIONS FOR SEPTEMBER 1999
-09GMT- --Temperature- --Soil temps-- -Earth temps-- Rain Fr. Pch
DD N dd ff ww VV Temp RH Max Min Gmin 5cm 10cm 20cm 30cm 50cm 1m E SS Rain Sun SLHTGF Press hrs hrs Evap
-----------------------------------------------------------------------------------------------------------------
01 5 33 05 02 97 19.5 68 25.4 11.4 6.0 14.0 14.5 15.0 17.6 17.5 16.9 90 0 0.0 9.0 000000 1023.0 0.0 0.0 1.9
02 7 00 00 10 95 19.3 64 26.6 11.9 9.0 14.5 15.0 15.5 17.8 17.6 16.9 90 0 0.0 11.5 000000 1023.0 0.0 0.0 2.4
03 3 36 02 10 94 19.9 68 27.4 13.6 10.0 16.0 16.5 17.0 18.0 17.7 16.9 90 0 0.0 11.0 000000 1020.0 0.0 0.0 3.2
04 1 36 02 02 97 19.8 65 27.3 11.8 5.7 15.0 15.5 16.5 17.8 17.7 16.9 90 0 0.0 9.5 000000 1021.0 0.0 0.0 3.2
05 1 33 02 02 96 20.2 73 27.1 13.2 10.0 16.0 16.5 17.0 18.0 17.6 17.0 90 0 4.4 9.0 000100 1015.5 1.3 0.0 2.0
06 1 00 00 44 08 20.0 78 26.8 12.3 10.5 15.5 16.0 16.5 18.2 17.8 17.0 10 0 0.0 10.0 000000 1011.0 0.0 0.0 3.8
07 7 22 02 01 96 19.6 73 22.9 14.5 11.7 16.9 17.2 18.1 18.4 17.9 17.0 10 0 0.0 5.3 000000 1010.5 0.0 0.0 1.3
08 7 22 02 02 96 18.5 84 22.2 9.3 7.9 13.9 14.8 16.6 17.8 17.8 17.0 00 0 0.3 0.9 000000 1017.5 0.4 0.0 2.1
09 6 25 02 01 97 16.5 79 21.0 12.1 10.0 15.6 16.4 17.5 17.7 17.4 17.0 10 0 0.0 9.0 000000 1024.5 0.0 0.0 2.2
10 1 00 00 02 97 16.8 76 24.1 9.0 7.0 13.2 14.2 16.2 17.3 17.3 17.0 90 0 0.0 10.8 000000 1027.0 0.0 0.0 1.7
11 7 32 02 05 96 21.4 80 27.8 15.3 13.4 16.6 16.8 17.5 17.5 17.2 16.9 90 0 0.1 5.9 000000 1016.5 0.1 0.0 2.6
12 7 26 02 01 97 17.4 83 21.3 16.1 15.3 17.8 18.2 18.5 18.0 17.6 16.8 90 0 0.2 5.1 000000 1014.5 0.5 0.0 1.8
13 7 36 02 03 97 12.0 88 19.5 9.0 7.2 14.2 14.9 16.6 17.4 17.5 16.9 90 0 2.0 4.7 000000 1014.0 3.5 0.0 1.5
14 8 36 02 60 94 12.0 89 14.8 11.7 10.0 14.3 14.9 15.8 16.8 17.0 16.9 10 0 3.4 0.0 000000 1015.0 9.0 0.0 0.5
15 8 35 02 02 94 13.2 95 17.3 11.6 11.1 14.2 14.6 15.6 15.2 16.6 16.7 10 0 2.2 0.1 000000 1014.5 3.1 0.0 0.1
16 7 22 05 02 94 17.3 77 18.1 9.6 7.5 13.4 13.8 14.9 15.8 16.2 16.5 10 0 3.3 1.0 000000 1008.0 2.4 0.0 1.1
17 1 27 02 02 96 15.0 71 20.1 8.2 6.7 12.0 12.8 14.5 15.5 15.9 16.3 10 0 0.4 9.9 000000 1007.5 0.2 0.0 0.8
18 2 36 09 02 97 17.3 80 18.9 9.7 7.5 12.8 13.7 14.6 15.5 15.8 16.1 10 0 0.4 2.9 000000 1004.5 1.0 0.0 1.5
19 8 18 14 02 97 16.8 86 17.8 15.3 13.8 15.2 15.2 15.7 15.9 15.8 16.1 10 0 15.4 0.3 000000 995.0 12.9 0.0 0.6
20 7 17 05 02 95 14.6 98 16.1 14.6 14.1 15.4 15.6 15.9 15.9 15.8 16.0 10 0 6.8 0.0 000000 988.5 5.3 0.0 0.2
21 9 00 00 45 04 14.7 98 20.2 11.1 9.3 14.4 14.6 15.1 15.5 15.7 15.9 10 0 tr 4.7 000000 996.0 0.0 0.0 1.0
22 8 23 02 02 97 18.2 88 19.7 13.7 10.8 15.0 15.4 15.8 16.0 15.7 15.9 10 0 7.9 2.3 000100 1000.5 1.9 0.0 0.7
23 3 18 05 25 97 16.1 88 19.9 14.1 11.6 14.3 15.3 16.8 16.0 15.6 15.8 10 0 2.8 5.4 000000 1003.5 2.0 0.0 1.1
24 7 20 13 02 97 17.5 87 19.4 14.9 12.1 14.4 15.5 16.0 16.2 15.8 15.8 10 0 7.9 3.4 000000 1009.0 6.5 0.0 0.9
25 6 22 13 25 97 16.2 95 18.8 12.6 10.1 15.3 15.3 15.5 16.0 15.8 15.8 10 0 8.8 2.2 000000 1007.5 6.0 0.0 0.7
26 4 22 05 02 97 13.8 92 17.1 10.3 8.4 14.8 14.6 15.2 15.9 15.8 15.8 10 0 4.0 4.5 000000 1004.5 3.5 0.0 0.8
27 6 20 05 02 97 14.8 87 18.2 12.5 10.0 13.9 13.8 15.2 15.8 15.6 15.8 10 0 1.3 3.4 000000 998.0 1.3 0.0 1.1
28 0 24 05 02 97 15.2 76 18.8 10.5 8.4 12.9 13.2 14.9 15.7 15.4 15.8 10 0 0.7 4.7 000000 1003.0 1.2 0.0 1.1
29 1 22 05 02 97 16.1 83 17.6 13.1 10.6 14.3 14.6 15.5 15.8 15.4 15.8 10 0 5.1 4.0 000100 999.5 3.1 0.0 1.0
30 7 22 05 02 97 15.0 82 18.1 12.1 9.7 13.3 13.8 14.8 15.5 15.4 15.7 10 0 0.0 4.7 000000 994.5 0.0 0.0 1.3
-----------------------------------------------------------------------------------------------------------------
Mean
4.9 4.0 16.8 82 21.0 12.2 9.8 14.6 15.1 16.0 16.7 16.6 16.4 1009.6
Total 77.4 155.2 65.2 0.0 44.2
1961-1990 Climatological
Mean5.7 4.4 83 19.2 10.0 7.9 13.2 13.8 15.0 15.5 15.4 15.3 57.7 137.0 1016.8 40
-----------------------------------------------------------------------------------------------------------------
Snow days 0; mean 0.0; 50% snow cover at 09h days 0; mean 0.0;
Hail days 0; mean 0.0; Ice pellets days 0; mean 0.0;
Thunder days 3; mean 0.9; Fog at 09h days 0; mean 0.6;
Gale days 0; mean 0.2;
Air frost days 0; mean 0.0 Days with 0.2mm rain days 19; mean 11.5*
Grass minimum frost days 0; mean 0.3 Days with 1.0mm rain days 14; mean 8.7*
Soil frost days 0 Days with 5.0mm rain days 6; mean 3.8*
Concrete frost days 0 Days with no sun days 2; mean 2.9
Air pressure: max - 1028.5mb/10th, min - 987.5mb/20th
Key
DD: date
07GMT observations...
N cloud cover (oktas, 9=obscured); dd wind direction (degrees/10); ff wind speed (knots);
VV visibility (00-50 metres/100, 94 very poor, 95 poor, 96 moderate, 97 good);
Soil temperatures are for 07GMT beneath a bare soil surface (degC);
Earth temperatures are for 07GMT beneath a grass surface (degC); SS snow depth (cm)
ww present weather code (01 cloud decreasing, 02 sky not changing, 05 haze, 10 mist,
25 recent rain shower, 44-45 fog, 60 intermittent light rain);
09GMT observations...
Temp temperature (degC); RH relative humidity (%); SS snow depth (cm);
Press air pressure (mb); E state of ground (00 dry, 10 moist, 20 wet, 90 cracked);
24 hour readings...
Max maximum temperature (degC) beginning 09GMT, Min minimum temperature (degC) ending 09GMT;
Gmin grass minimum temperature (degC) ending 09GMT; Pch Evap Piche evaporation (ml) beginning O9GMT;
Rain rainfall beginning 09GMT (mm); Sun sunshine (hours) sunrise-sunset;
Rain hrs hours of rainfall (>0.1mm/hr) 09-09GMT; Fr. hrs hours of air frost (00-24GMT)
Days with...
S snow/sleet falling; L 50% snow cover at 09GMT; H>4 hail falling; F fog at 09GMT;
H<5 ice pellets, snow grains, snow pellets falling; T thunder heard; G gale;
* Averages for Hurley (4km away)
Warmest September for 50 years; the maximum on the 11th was unusually warm for so late in the month.
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MAIDENHEAD METEOROLOGICAL OBSERVATIONS FOR OCTOBER 1999
-09GMT- --Temperature- --Soil temps-- -Earth temps-- Rain Fr. Pch
DD N dd ff ww VV Temp RH Max Min Gmin 5cm 10cm 20cm 30cm 50cm 1m E SS Rain Sun SLHTGF Press hrs hrs Evap
-----------------------------------------------------------------------------------------------------------------
01 8 22 05 02 97 14.3 72 15.5 9.8 8.1 12.5 12.8 14.4 15.4 15.2 15.6 10 0 8.0 3.6 000000 995.5 3.4 0.0 2.0
02 1 22 09 02 96 10.7 82 15.2 8.5 8.5 12.7 13.1 14.4 15.2 15.0 15.6 10 0 0.4 8.4 000000 1004.0 0.3 0.0 1.4
03 1 24 05 02 97 12.5 80 15.6 6.1 4.6 10.6 11.1 12.8 14.5 14.8 15.6 10 0 0.8 5.4 000000 999.0 1.3 0.0 1.0
04 2 28 09 02 97 9.9 72 13.5 6.1 3.7 9.9 10.3 12.4 14.0 14.4 15.3 10 0 0.0 8.6 000000 1012.0 0.0 0.0 1.4
05 0 27 02 02 97 8.0 85 13.8 1.1 0.5 7.9 8.9 11.2 13.2 13.8 15.1 10 0 0.0 8.3 000000 1028.0 0.0 0.0 1.2
06 6 00 00 02 97 6.8 88 14.8 0.7 0.5 7.5 8.2 10.6 12.7 13.5 14.9 10 0 0.0 9.7 000000 1032.0 0.0 0.0 1.0
07 8 27 02 03 97 11.5 77 15.6 3.8 2.1 8.7 9.2 10.9 12.4 13.0 14.6 10 0 1.1 0.0 000000 1028.0 2.0 0.0 0.5
08 8 27 02 52 94 15.6 86 18.9 8.1 7.3 12.1 11.8 12.2 12.5 12.8 14.3 10 0 0.0 2.7 000000 1023.5 0.0 0.0 0.9
09 8 26 02 02 97 16.7 77 18.6 12.1 8.8 13.3 12.9 13.2 13.1 13.2 14.1 10 0 0.1 2.5 000000 1023.0 0.1 0.0 0.9
10 6 23 02 02 97 16.4 89 18.3 13.2 9.6 13.8 13.8 13.9 13.6 13.5 14.1 10 0 tr 0.4 000000 1022.5 0.0 0.0 0.8
11 5 29 02 02 97 12.0 65 14.3 11.1 7.5 12.9 13.4 14.3 14.0 13.7 14.1 10 0 0.0 7.0 000000 1027.0 0.0 0.0 1.0
12 3 00 00 02 96 8.3 82 15.3 2.3 1.0 8.7 9.7 11.9 13.4 13.6 14.1 10 0 0.0 7.8 000000 1031.5 0.0 0.0 1.2
13 3 00 00 02 94 9.3 77 15.2 2.0 1.1 8.3 8.9 11.0 12.6 13.1 14.1 10 0 0.0 8.9 000000 1032.0 0.0 0.0 1.6
14 0 04 02 11 94 8.5 82 16.1 2.4 0.7 7.8 8.6 10.0 12.1 12.6 14.0 10 0 0.0 8.4 000000 1030.0 0.0 0.0 1.9
15 7 00 00 02 96 11.6 90 16.5 8.0 7.5 10.9 10.6 11.4 12.1 12.4 13.8 10 0 0.0 6.0 000000 1024.5 0.0 0.0 1.2
16 0 00 00 02 94 11.0 85 16.0 5.9 3.6 9.1 9.6 11.1 12.1 12.4 13.6 10 0 0.0 8.2 000000 1024.0 0.0 0.0 1.3
17 5 05 02 02 97 10.4 83 14.7 6.6 4.4 9.1 9.4 10.9 11.9 12.4 13.5 10 0 0.0 8.8 000000 1020.5 0.0 0.0 1.8
18 1 09 09 02 97 9.6 72 13.2 6.1 4.0 8.0 8.6 10.7 11.6 12.2 13.4 10 0 0.0 9.3 000000 1020.0 0.0 0.0 2.4
19 3 08 13 02 97 9.0 66 12.6 5.6 3.5 7.8 8.4 10.0 11.5 11.8 13.2 10 0 0.0 8.4 000000 1015.5 0.0 0.0 2.7
20 8 07 05 02 97 8.6 67 10.0 5.8 3.9 7.3 8.1 9.5 10.9 11.5 13.0 10 0 7.7 0.0 000000 1008.0 13.0 0.0 1.2
21 8 07 05 60 94 8.9 93 14.0 7.2 7.0 8.9 9.5 10.2 10.7 11.3 12.9 10 0 6.2 0.0 000000 999.5 5.1 0.0 0.2
22 4 17 05 02 96 14.0 88 15.6 9.7 6.3 9.6 9.8 10.3 11.0 11.2 12.7 10 0 11.0 0.1 000000 996.0 5.8 0.0 0.4
23 7 18 05 02 97 12.9 92 15.7 9.0 5.8 11.3 11.0 11.4 11.5 11.4 12.5 10 0 10.6 1.7 000100 990.5 10.2 0.0 0.3
24 8 23 13 63 94 12.0 94 12.1 9.5 6.5 11.4 11.2 11.5 11.6 11.7 12.6 10 0 5.5 0.5 000000 975.5 4.6 0.0 0.5
25 7 22 04 02 97 9.7 93 15.6 7.7 3.5 10.0 10.7 11.2 11.5 11.5 12.5 10 0 0.0 6.9 000000 993.0 0.0 0.0 0.5
26 6 23 05 01 97 11.5 93 15.6 3.9 2.1 11.4 11.4 11.4 11.4 11.4 12.5 10 0 0.0 3.2 000000 1014.5 0.0 0.0 0.1
27 0 22 02 11 94 9.0 90 15.3 6.0 3.1 8.8 9.2 10.2 11.1 11.4 12.5 10 0 0.0 7.7 000000 1025.5 0.0 0.0 0.9
28 5 23 02 02 97 12.2 89 16.4 8.3 6.5 9.9 7.2 10.6 11.0 11.3 12.4 10 0 0.2 7.1 000000 1024.5 0.4 0.0 0.6
29 9 00 00 45 03 8.8 99 15.5 8.1 4.5 10.2 10.3 10.9 11.2 11.3 12.4 10 0 0.5 0.0 000001 1026.0 1.6 0.0 0.4
30 8 21 02 02 94 15.5 89 17.3 8.8 9.5 11.8 11.6 11.6 11.5 11.5 12.3 10 0 1.6 1.2 000000 1006.5 0.5 0.0 1.2
31 0 20 02 02 97 11.6 80 15.9 9.7 6.0 9.6 10.0 11.0 11.8 11.7 12.3 10 0 0.2 6.8 000000 1017.0 0.5 0.0 2.1
-----------------------------------------------------------------------------------------------------------------
Mean
4.5 3.7 11.2 83 15.2 6.9 4.9 10.1 10.3 11.5 12.4 12.6 13.7 1015.1
Total 53.9 157.6 48.8 0.0 34.6
1961-1990 Climatological
Mean5.4 5.1 88 15.3 7.5 5.3 10.1 10.8 11.7 12.4 12.6 13.2 60.4 97.0 1015.7 46
-----------------------------------------------------------------------------------------------------------------
Snow days 0; mean 0.0; 50% snow cover at 09h days 0; mean 0.0;
Hail days 0; mean 0.0; Ice pellets days 0; mean 0.1;
Thunder days 1; mean 0.3; Fog at 09h days 0; mean 2.9;
Gale days 0; mean 0.3;
Air frost days 0; mean 0.6 Days with 0.2mm rain days 13; mean 14.3*
Grass minimum frost days 0; mean 3.9 Days with 1.0mm rain days 8; mean 10.0*
Soil frost days 0 Days with 5.0mm rain days 6; mean 3.8*
Concrete frost days 0 Days with no sun days 4; mean 6.8
Air pressure: max - 1032.0mb/6th, min - 975.5mb/24th
Key
DD: date
07GMT observations...
N cloud cover (oktas, 9=obscured); dd wind direction (degrees/10); ff wind speed (knots);
VV visibility (00-50 metres/100, 94 very poor, 95 poor, 96 moderate, 97 good);
Soil temperatures are for 07GMT beneath a bare soil surface (degC);
Earth temperatures are for 07GMT beneath a grass surface (degC); SS snow depth (cm)
ww present weather code (01 cloud decreasing, 02 sky not changing, 03 cloud increasing,
11 shallow fog patches, 45 fog, 52 intermittent moderate drizzle, 60 intermittent light rain,
63 continuous moderate rain);
09GMT observations...
Temp temperature (degC); RH relative humidity (%); SS snow depth (cm);
Press air pressure (mb); E state of ground (00 dry, 10 moist, 20 wet);
24 hour readings...
Max maximum temperature (degC) beginning 09GMT, Min minimum temperature (degC) ending 09GMT;
Gmin grass minimum temperature (degC) ending 09GMT; Pch Evap Piche evapoartion (ml) beginning O9GMT;
Rain rainfall beginning 09GMT (mm); Sun sunshine (hours) sunrise-sunset;
Rain hrs hours of rainfall (>0.1mm/hr) 09-09GMT; Fr. hrs hours of air frost (00-24GMT)
Days with...
S snow/sleet falling; L 50% snow cover at 09GMT; H>4 hail falling; F fog at 09GMT;
H<5 ice pellets, snow grains, snow pellets falling; T thunder heard; G gale;
* Averages for Hurley (4km away)
A very sunny month.
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MAIDENHEAD METEOROLOGICAL OBSERVATIONS FOR NOVEMBER 1999
-09GMT- --Temperature- --Soil temps-- -Earth temps-- Rain Fr. Pch
DD N dd ff ww VV Temp RH Max Min Gmin 5cm 10cm 20cm 30cm 50cm 1m E SS Rain Sun SLHTGF Press hrs hrs Evap
-----------------------------------------------------------------------------------------------------------------
01 8 20 13 02 97 15.9 82 17.3 11.6 10.1 11.6 11.6 11.7 11.8 11.7 12.3 10 0 0.3 0.1 000000 1008.5 0.8 0.0 1.2
02 7 25 02 02 97 10.4 77 14.0 9.4 6.2 10.3 10.7 11.5 11.9 11.8 12.4 10 0 0.0 6.4 000000 1018.5 0.0 0.0 1.3
03 7 27 02 03 97 10.9 87 13.7 3.9 1.1 8.8 9.0 10.0 11.2 11.7 12.4 10 0 tr 1.2 000000 1031.0 0.0 0.0 0.3
04 3 26 02 11 94 9.4 87 13.6 5.5 2.1 8.3 9.4 10.2 11.0 11.4 12.4 10 0 0.0 3.4 000000 1025.5 0.0 0.0 1.4
05 8 22 13 02 97 12.4 74 12.5 8.5 4.9 9.9 9.9 10.4 10.9 11.3 12.2 10 0 7.7 0.0 000000 1003.0 4.7 0.0 1.0
06 3 31 13 02 97 7.8 83 11.0 6.5 3.6 8.0 8.3 9.8 10.7 11.0 12.1 10 0 0.2 5.8 000000 1010.5 0.2 0.0 1.4
07 2 00 00 03 97 4.2 89 10.4 1.7 -1.4 6.4 7.0 8.8 10.0 10.7 12.0 10 0 0.0 2.9 000000 1027.5 0.0 0.0 0.6
08 7 00 00 02 97 9.9 93 12.8 4.2 7.8 9.4 9.3 9.7 10.0 10.4 11.9 10 0 0.1 0.0 000000 1031.0 0.3 0.0 0.6
09 8 35 02 02 97 10.2 90 12.8 8.7 5.0 9.7 9.8 10.3 10.5 10.5 11.7 10 0 0.0 4.9 000000 1039.0 0.0 0.0 1.3
10 1 02 05 02 97 9.2 87 10.6 7.4 5.2 8.5 8.7 9.4 10.3 10.7 11.7 10 0 tr 0.0 000000 1040.0 0.0 0.0 1.4
11 7 07 09 02 97 10.0 78 10.4 7.3 4.9 7.9 8.2 9.1 10.0 10.4 11.6 10 0 0.1 0.0 000000 1039.0 0.1 0.0 1.0
12 2 02 05 02 97 7.1 80 10.5 5.2 2.7 7.9 8.3 9.3 10.0 10.3 11.5 10 0 0.0 5.1 000000 1032.5 0.0 0.0 1.7
13 2 03 09 02 97 6.4 89 10.8 4.2 1.5 6.9 7.2 8.6 9.6 10.1 11.4 10 0 tr 4.8 000000 1029.0 0.0 0.0 1.3
14 8 02 09 02 97 9.7 93 10.9 6.4 7.6 8.9 8.9 9.3 9.5 10.0 11.3 10 0 0.2 0.3 000000 1024.5 0.3 0.0 1.4
15 8 09 05 02 97 6.5 81 9.7 5.4 1.6 7.8 7.7 8.8 9.6 9.9 11.1 10 0 2.1 2.7 000000 1025.5 3.0 0.0 0.5
16 3 33 02 01 97 7.0 82 10.0 4.9 1.2 7.2 7.7 8.5 9.1 9.6 11.1 10 0 2.4 5.2 000000 1019.0 0.4 0.0 0.8
17 1 36 09 02 97 3.7 81 6.4 2.2 -0.5 5.3 5.6 7.1 8.6 9.4 11.0 10 0 3.1 6.8 000000 1019.5 4.5 0.0 1.3
18 7 36 05 01 97 4.7 78 5.8 0.4 -3.0 5.4 5.5 6.4 7.9 8.8 10.8 10 0 0.1 6.5 000000 1013.0 0.1 0.0 1.5
19 4 35 19 80 97 4.5 90 7.5 2.7 0.5 3.3 3.9 5.5 7.4 8.4 10.5 10 0 0.2 3.6 000000 1019.5 0.2 0.0 1.3
20 5 35 09 80 97 4.5 85 6.6 3.4 1.5 4.2 4.6 5.6 7.0 7.8 10.3 10 0 0.0 1.1 000000 1025.0 0.0 0.0 1.5
21 7 02 09 02 97 4.1 83 7.5 3.3 0.5 4.5 4.5 5.7 6.9 7.6 10.0 10 0 2.1 1.3 000000 1022.0 2.2 0.0 0.8
22 8 27 05 02 97 5.0 93 7.9 3.3 1.2 4.8 5.0 6.0 6.9 7.5 9.8 10 0 0.1 0.1 000000 1017.0 0.1 0.0 0.2
23 8 23 02 02 96 5.5 93 12.0 1.2 -1.7 4.5 4.6 5.9 6.8 7.5 9.5 10 0 tr 0.0 000000 1023.0 0.0 0.0 0.3
24 8 22 05 02 97 12.0 82 13.0 5.5 6.1 7.6 7.2 7.2 7.2 7.6 9.5 10 0 1.5 0.2 000000 1024.5 0.8 0.0 1.4
25 8 20 05 21 96 12.1 93 13.2 10.8 7.8 9.2 8.8 8.5 8.0 8.8 9.4 10 0 0.0 4.5 000000 1027.0 0.0 0.0 1.0
26 7 20 13 02 97 10.1 86 11.1 10.1 6.6 8.7 8.5 8.7 8.6 8.3 9.4 10 0 6.8 0.0 000000 1020.5 4.8 0.0 1.2
27 0 24 02 10 95 5.1 97 12.9 3.9 0.5 7.0 7.3 8.4 8.6 8.6 9.6 10 0 0.2 5.6 000000 1021.5 0.1 0.0 1.0
28 7 23 13 02 97 12.1 86 13.4 5.1 6.9 9.2 8.7 8.5 8.7 8.6 9.7 10 0 4.2 1.4 000000 1016.5 5.2 0.0 2.0
29 8 23 02 60 95 9.0 95 9.1 8.5 7.8 8.7 8.8 9.1 9.0 8.8 9.8 10 0 5.3 0.0 000000 1020.0 8.0 0.0 0.2
30 4 00 00 03 97 5.5 80 12.4 -0.2 -3.1 5.1 5.3 7.0 8.5 8.7 9.8 10 0 tr 0.0 000000 1028.0 0.0 0.2 1.1
-----------------------------------------------------------------------------------------------------------------
Mean
5.5 6.3 8.2 86 11.0 5.4 3.2 7.5 7.7 8.5 9.2 9.6 10.9 1023.4
Total 36.7 73.9 35.8 0.2 32.0
Climatological
Mean5.6 5.5 89 10.4 3.8 1.7 6.1 6.7 7.7 8.6 9.2 10.6 62.3 60.4 1014.6 53
-----------------------------------------------------------------------------------------------------------------
Snow days 0; mean 0.6; 50% snow cover at 09h days 0; mean 0.1;
Hail days 0; mean 0.1; Ice pellets days 0; mean 0.1;
Thunder days 0; mean 0.2; Fog at 09h days 0; mean 3.4;
Gale days 0; mean 0.2;
Air frost days 1; mean 5.6 Days with 0.2mm rain days 14; mean 15.0*
Grass minimum frost days 5; mean 11.1 Days with 1.0mm rain days 9; mean 10.6*
Soil frost days 0 Days with 5.0mm rain days 3; mean 4.4*
Days with no sun days 8; mean 10.3
Air pressure: max - 1040.5mb/9th,10th, min - 994.0mb/5th
Key
DD: date
07GMT observations...
N cloud cover (oktas, 9=obscured); dd wind direction (degrees/10); ff wind speed (knots);
VV visibility (00-50 metres/100, 94 very poor, 95 poor, 96 moderate, 97 good);
Soil temperatures are for 07GMT beneath a bare soil surface (degC);
Earth temperatures are for 07GMT beneath a grass surface (degC); SS snow depth (cm)
ww present weather code (01 cloud decreasing, 02 sky not changing, 03 cloud increasing, 10 mist,
11 shallow fog patches, 21 recent rain, 60 intermittent light rain, 80 light rain shower);
09GMT observations...
Temp temperature (degC); RH relative humidity (%); SS snow depth (cm);
Press air pressure (mb); E state of ground (00 dry, 10 moist, 20 wet);
24 hour readings...
Max maximum temperature (degC) beginning 09GMT, Min minimum temperature (degC) ending 09GMT;
Gmin grass minimum temperature (degC) ending 09GMT; Pch Evap Piche evaporation (ml) beginning O9GMT;
Rain rainfall beginning 09GMT (mm); Sun sunshine (hours) sunrise-sunset;
Rain hrs hours of rainfall (>0.1mm/hr) 09-09GMT; Fr. hrs hours of air frost (00-24GMT)
Days with...
S snow/sleet falling; L 50% snow cover at 09GMT; H>4 hail falling; F fog at 09GMT;
H<5 ice pellets, snow grains, snow pellets falling; T thunder heard; G gale;
* Averages for Hurley (4km away)
Almost no air frost. Driest November since 1990, and most anticyclonic November since 1990 despite lack of fog.
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MAIDENHEAD METEOROLOGICAL OBSERVATIONS FOR DECEMBER 1999
-09GMT- --Temperature- --Soil temps-- -Earth temps-- Rain Fr. Pch
DD N dd ff ww VV Temp RH Max Min Gmin 5cm 10cm 20cm 30cm 50cm 1m E SS Rain Sun SLHTGF Press hrs hrs Evap
-----------------------------------------------------------------------------------------------------------------
01 8 27 05 02 97 12.0 95 12.4 5.5 9.0 9.3 8.8 8.6 8.4 8.6 9.8 10 0 0.3 3.4 000000 1021.0 0.4 0.0 1.1
02 6 31 02 03 97 5.5 78 11.5 2.8 -1.6 5.6 5.9 7.4 8.5 8.7 9.8 10 0 tr 5.0 000000 1026.0 0.0 0.0 1.5
03 8 23 19 02 97 11.5 78 12.6 5.5 4.4 7.6 7.3 7.7 8.1 8.4 9.7 10 0 1.1 0.5 005000 1006.0 0.2 0.0 1.9
04 0 32 05 02 97 4.2 89 7.5 2.5 -1.3 4.4 4.7 6.4 7.9 8.3 9.6 10 0 0.1 5.5 000000 1012.0 0.1 0.0 1.0
05 2 00 00 02 97 0.7 94 9.9 -0.2 -3.9 2.8 4.3 4.9 6.9 7.7 9.6 10 0 0.2 4.7 000000 1026.0 0.9 0.5 1.3
06 8 25 09 50 97 9.9 87 11.8 0.7 4.2 5.8 5.8 6.0 6.7 7.2 9.2 10 0 1.0 0.0 000000 1019.0 1.3 0.0 1.1
07 7 21 05 02 97 9.0 85 11.0 8.8 4.0 7.6 7.3 7.8 7.6 7.6 9.1 10 0 2.0 1.3 000000 1010.5 0.5 0.0 1.0
08 7 25 02 02 97 9.2 87 11.0 3.8 4.4 5.1 4.9 6.1 7.4 7.7 9.1 10 0 5.0 0.0 000000 1007.0 2.1 0.0 1.7
09 0 32 13 02 97 6.2 73 9.0 5.2 1.9 4.9 4.9 6.2 7.4 7.6 9.0 10 0 0.2 5.9 000000 996.0 0.1 0.0 1.5
10 6 34 02 02 97 5.2 86 11.9 2.7 -2.4 4.4 4.2 5.7 6.9 7.4 9.0 10 0 4.7 3.3 000000 1003.0 6.1 0.0 1.4
11 8 25 09 51 95 11.9 91 12.5 4.9 4.0 7.1 6.5 6.3 6.9 7.3 8.9 10 0 3.3 0.0 000000 991.5 1.2 0.0 1.1
12 8 26 05 02 97 7.5 77 8.6 7.3 4.2 7.1 7.0 7.5 7.6 7.6 8.9 10 0 8.4 0.4 000000 988.0 4.4 0.0 0.8
13 0 02 02 02 96 3.1 95 7.3 1.8 -1.6 3.8 4.3 5.7 7.1 7.6 8.9 10 0 4.8 0.3 000000 1000.5 2.1 0.0 0.9
14 0 00 00 02 97 0.1 97 3.6 -0.2 -3.7 2.9 3.8 4.9 6.4 7.2 8.7 10 0 0.2 2.9 000000 1000.0 0.7 4.1 0.9
15 0 32 13 02 97 2.2 82 3.8 -1.3 -4.6 1.9 2.8 3.8 5.5 6.6 8.5 40 0 0.0 1.9 100000 1017.0 0.0 0.0 1.1
16 0 32 05 02 97 2.3 96 8.7 0.4 -3.6 2.1 2.1 3.5 5.1 6.0 8.3 40 0 0.2 4.2 100000 1026.5 0.2 0.0 0.7
17 7 23 24 02 97 8.7 85 11.0 2.3 -2.6 4.6 4.2 4.4 5.0 5.7 8.0 10 0 2.5 0.0 000000 1010.0 3.2 0.0 0.8
18 7 27 02 02 97 2.0 93 3.9 2.0 -2.2 4.2 4.2 5.1 5.8 6.0 7.9 10 0 4.4 0.0 500000 1017.0 4.6 0.0 0.5
19 0 33 09 03 97 -2.0 92 0.5 -2.0 -4.0 1.7 2.1 3.8 5.3 6.0 7.9 X2 1 0.0 5.9 010000 1023.0 0.0 15.6 0.1
20 0 00 00 02 97 -5.5 95 2.5 -6.3 -7.2 0.6 0.8 2.5 4.4 5.3 7.8 X1 1 2.2 2.0 000000 1030.0 2.7 21.6 0.0
21 8 22 02 71 94 2.1 95 6.4 -5.5 -5.0 0.7 0.7 2.2 3.8 4.6 7.4 X1 0 0.9 0.0 500000 1023.5 1.2 0.9 0.5
22 8 23 05 02 97 6.4 85 12.2 2.1 1.2 3.2 2.6 2.9 3.9 4.5 7.1 10 0 11.1 0.0 000000 1018.0 6.0 0.0 0.5
23 0 26 02 10 96 4.7 95 10.6 2.7 -1.4 3.6 3.8 4.4 5.0 4.9 6.9 20 0 12.6 3.6 000000 1018.5 6.2 0.0 1.2
24 8 26 09 02 97 10.0 92 12.8 4.7 7.0 7.1 6.6 6.3 5.8 5.4 6.9 20 0 18.1 0.0 000000 1002.0 6.8 0.0 1.4
25 5 33 05 01 97 4.8 77 6.6 3.1 0.4 5.4 5.6 6.8 6.6 6.2 7.0 20 0 6.6 0.3 100000 991.0 4.5 0.0 0.8
26 1 31 02 02 97 3.7 91 8.6 2.5 -0.6 4.0 4.3 5.4 6.0 6.2 7.1 10 0 3.3 2.4 000000 988.0 2.0 0.0 0.7
27 3 27 02 02 96 1.5 96 4.0 0.7 -3.9 2.3 2.5 4.1 5.5 5.8 7.1 10 0 0.1 0.0 000000 995.5 0.1 0.0 0.2
28 8 22 02 02 97 2.9 93 4.6 1.5 -3.9 3.2 3.1 4.0 5.0 5.4 7.1 10 0 0.0 1.9 000000 1002.0 0.0 2.4 0.3
29 4 24 02 03 97 0.0 94 5.8 -1.8 -5.3 1.4 1.6 3.0 4.5 5.2 7.0 40 0 2.0 1.2 000000 1017.0 1.3 8.6 0.2
30 8 22 05 61 95 2.4 98 7.2 -0.2 -4.7 1.8 1.7 2.8 4.0 4.8 6.8 10 0 11.4 0.0 000000 1022.0 10.8 1.5 0.1
31 8 23 02 02 96 4.9 96 8.4 2.4 3.0 3.9 4.1 4.4 4.5 4.7 6.6 10 0 1.8 0.0 000000 1021.5 0.8 0.0 0.1
-----------------------------------------------------------------------------------------------------------------
Mean
4.6 5.5 4.7 89 8.3 1.9 -0.5 4.2 4.3 5.2 6.1 6.5 8.2 1010.6
Total 108.5 56.6 70.5 55.2 26.4
Climatological Mean
6.0 5.7 89 7.8 2.0 0.0 4.3 4.5 5.3 6.0 6.7 8.1 64.0 39.7 1015.0 59
-----------------------------------------------------------------------------------------------------------------
Snow days 5; mean 1.9; 50% snow cover at 09h days 1; mean 1.5;
Hail days 1; mean 0.1; Ice pellets days 0; mean 0.3;
Thunder days 0; mean 0.2; Fog at 09h days 0; mean 2.2;
Gale days 0; mean 0.2;
Air frost days 8; mean 8.8 Days with 0.2mm rain days 25; mean 16.2*
Grass minimum frost days 19; mean 15.9 Days with 1.0mm rain days 19; mean 11.2*
Soil frost days 10 Days with 5.0mm rain days 7; mean 5.2*
Days with no sun days 11; mean 15.0
Air pressure: max - 1030.0mb/20th, min - 980.0mb/25th
Key
DD: date
07GMT observations...
N cloud cover (oktas, 9=obscured); dd wind direction (degrees/10); ff wind speed (knots);
VV visibility (00-50 metres/100, 94 very poor, 95 poor, 96 moderate, 97 good);
Soil temperatures are for 07GMT beneath a bare soil surface (degC);
Earth temperatures are for 07GMT beneath a grass surface (degC); SS snow depth (cm)
ww present weather code (01 cloud decreasing, 02 sky not changing, 03 cloud increasing, 10 mist,
50 intermittent light drizzle, 51 continuous light drizzle, 61 continuous light rain,
71 continuous light snow);
09GMT observations...
Temp temperature (degC); RH relative humidity (%); SS snow depth (cm); Press air pressure (mb);
E state of ground (10 moist, 20 wet, 40 frozen, X1 under half snow cover, X2 over half snow cover);
24 hour readings...
Max maximum temperature (degC) beginning 09GMT, Min minimum temperature (degC) ending 09GMT;
Gmin grass minimum temperature (degC) ending 09GMT; Pch Evap Piche evaporation (ml) beginning O9GMT;
Rain rainfall beginning 09GMT (mm); Sun sunshine (hours) sunrise-sunset;
Rain hrs hours of rainfall (>0.1mm/hr) 09-09GMT; Fr. hrs hours of air frost (00-24GMT)
Days with...
S snow/sleet falling; L 50% snow cover at 09GMT; H>4 hail falling; F fog at 09GMT;
H<5 ice pellets, snow grains, snow pellets falling; T thunder heard; G gale;
* Averages for Hurley (4km away)
-6.3degC on the 20th was the lowest in any month since December 1991.
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Monthly and annual summary statistics for 1999 at Boyn Hill (Maidenhead, Berkshire)
Comparison with recent years of annual values
--------Temperature (degC)-------- -Rainfall (mm)- Sunshine (hrs) Days with Piche
Mean Max Min Grass Total >= >= Total no AF GF SF SL T F09 Evaporation
Air 30cm 100cm Air Air Min 0.2 1.0 sun (ml)
1989 11.7 11.9 11.8 33.0 -6.3 -10.4 604.3 145 106 1802.8 60 35 88 4 0 15 13 -
1990 11.6 11.9 11.8 35.3 -4.1 -7.2 492.5 132 101 1772.3 50 21 92 5 1 11 7 -
1991 10.5 10.7 10.7 28.5 -8.4 -13.9 527.2 145 96 1364.3 80 49 95 10 9 10 13 -
1992 10.9 11.2 11.1 29.5 -6.2 -9.5 712.6 170 118 1328.7 80 43 91 5 1 15 14 -
1993 10.6 10.9 10.9 27.4 -4.8 -7.8 681.5 151 112 1333.1 78 31 83 8 0 12 11 555.8
1994 11.4 11.4 11.2 31.9 -5.2 -7.6 649.0 172 131 1445.9 81 27 81 7 3 9 11 581.5
1995 11.7 12.1 11.9 33.9 -5.3 -7.8 627.7 141 105 1640.7 71 44 70 15 2 16 8 675.4
1996 10.3 10.7 10.6 31.4 -4.8 -8.3 500.9 133 88 1496.4 75 57 96 21 8 8 8 614.6
1997 11.5 11.6 11.4 31.3 -5.3 -9.1 553.0 139 105 1630.0 68 43 83 7 0 13 15 579.7
1998 11.4 11.6 11.5 29.8 -4.0 -8.2 798.9 176 133 1397.4 69 30 84 5 0 15 5 517.2
1999 11.5 11.9 11.8 31.2 -6.3 -8.8 742.6 175 124 1612.8 54 30 72 11 2 18 4 570.3
(AF=air frost, GF=ground frost, SF=snow falling, SL:>=50 per cent snow cover at 09GMT, T=thunder, F09=fog at 09GMT)
Cloud amount Wind speed Humidity Grass minimum temperature
(oktas) at 07h (kts) at 09h (%) (degC)
Mean Anomaly Mean Anomaly Mean Anomaly High Low Mean Anomaly
J 5.5 0.0 5.2 -1.5 91 2 9.8 -7.1 0.1 0.9
F 5.3 -0.4 5.8 -0.7 86 -2 6.0 -8.8 -0.4 0.9
M 5.5 -0.5 3.3 -3.0 87 4 8.0 -5.7 1.8 1.8
A 5.9 0.8 4.6 -1.5 78 1 10.6 -2.2 3.7 1.7
M 5.4 0.5 5.0 -1.4 75 2 14.5 3.9 7.7 2.1
J 4.8 -0.5 3.9 -1.7 75 3 14.1 3.6 8.9 -0.1
J 5.7 0.5 4.6 -0.9 66 -7 16.5 6.4 11.6 0.8
A 5.7 0.5 3.4 -1.9 75 -2 16.8 5.7 10.7 0.2
S 4.9 -0.8 4.0 -0.4 82 -1 15.3 5.7 9.8 1.9
O 4.5 -0.9 3.7 -1.4 83 -5 9.6 0.5 4.9 -0.4
N 5.5 -0.1 6.3 0.8 86 -3 10.1 -3.1 3.2 1.5
D 4.6 -1.4 5.5 -0.2 89 0 9.0 -7.2 -0.5 -0.5
1999 5.3 -0.2 4.6 -1.2 81 -1 16.8 -8.8 5.2 0.9
Maximum temperature Minimum temperature Monthly mean
(degC) (degC) Temperature (degC)
High Low Mean Anomaly High Low Mean Anomaly Mean Anomaly
J 14.2 2.3 9.0 1.9 11.3 -2.5 3.1 2.0 6.1 2.0
F 13.7 2.8 9.3 1.5 9.2 -4.8 2.5 1.2 5.9 1.3
M 20.3 5.4 12.4 1.7 11.2 -2.4 4.2 1.5 8.3 1.6
A 21.6 9.4 15.3 1.8 11.5 -1.8 6.0 1.2 10.7 1.6
M 26.5 14.9 19.0 1.9 15.8 6.1 9.8 1.9 14.4 1.9
J 27.0 16.4 20.5 0.5 14.5 5.6 10.3 -0.4 15.4 0.0
J 30.9 16.9 24.7 2.6 18.6 7.8 13.6 1.1 19.1 2.2
A 31.2 16.0 22.3 0.6 18.2 8.1 12.9 0.7 17.6 0.7
S 27.8 14.8 21.0 1.8 16.1 8.2 12.2 2.2 16.6 1.4
O 18.9 10.0 15.2 -0.1 13.2 0.7 6.9 -0.6 11.1 -0.3
N 17.3 5.8 11.0 0.6 11.6 -0.2 5.4 1.6 8.2 1.1
D 12.8 0.5 8.3 0.5 8.8 -6.3 1.9 -0.1 5.1 0.2
1999 31.2 0.5 15.7 1.3 18.6 -6.3 7.4 1.0 11.5 1.1
Soil temperatures recorded at 07h (degC)
------5cm depth------- ------10cm depth------ ------20cm depth------
High Low Mean Anomaly High Low Mean Anomaly High Low Mean Anomaly
J 9.7 0.5 4.9 1.6 8.9 1.3 4.9 1.6 8.3 3.2 5.7 1.6
F 8.0 0.4 4.1 1.2 8.4 0.7 4.2 0.9 7.5 2.2 5.2 1.1
M 9.4 1.7 6.2 1.6 9.4 2.2 6.3 1.4 9.8 4.1 7.3 1.5
A 12.1 4.1 8.8 1.6 11.7 4.4 8.9 1.2 11.7 7.3 10.0 1.8
M 17.1 10.5 12.9 2.2 17.3 11.1 13.1 2.4 17.7 12.4 14.1 2.0
J 17.2 12.1 14.8 0.5 19.1 12.7 15.2 0.7 18.5 14.5 16.3 0.7
J 19.9 14.8 17.6 1.6 19.4 15.1 17.9 1.5 20.6 16.9 19.1 2.2
A 20.4 13.3 16.1 0.5 21.0 14.2 16.4 0.2 21.6 15.0 17.5 0.3
S 17.8 12.8 14.6 1.4 18.2 12.8 15.1 1.5 18.5 14.5 16.0 1.0
O 13.8 7.3 10.1 0.0 13.8 7.2 10.3 -0.5 14.4 9.5 11.5 -0.2
N 11.6 3.3 7.5 1.4 11.6 3.9 7.7 1.0 11.7 5.5 8.5 0.8
D 9.3 0.6 4.2 -0.1 8.8 0.7 4.3 -0.2 8.6 2.2 5.2 -0.1
1999 20.4 0.4 10.2 1.1 21.0 0.7 10.4 1.0 21.6 2.2 11.4 1.0
Earth temperatures recorded at 07h (degC)
------30cm depth------ ------50cm depth------ ------100cm depth-----
High Low Mean Anomaly High Low Mean Anomaly High Low Mean Anomaly
J 8.0 4.4 6.3 1.6 7.6 4.7 6.3 0.9 8.0 6.7 7.3 0.7
F 7.2 3.6 5.8 1.2 6.7 4.3 5.8 0.7 7.3 6.1 6.7 0.7
M 9.6 5.8 7.8 1.9 8.8 5.8 7.5 1.3 8.5 6.9 7.6 1.2
A 11.9 8.9 10.4 1.7 11.2 9.1 10.0 1.7 10.2 8.6 9.6 1.6
M 16.8 12.7 14.2 2.0 15.5 11.4 13.3 2.1 13.7 10.4 12.1 2.0
J 18.1 14.9 16.4 1.2 17.0 14.5 15.7 1.6 15.6 13.7 14.5 2.0
J 20.0 17.1 18.9 1.6 19.2 16.4 18.2 1.9 17.4 15.4 16.7 1.6
A 21.0 16.6 18.2 1.0 20.0 16.4 17.9 0.9 18.1 16.3 17.2 1.1
S 18.4 15.2 16.7 1.2 17.9 15.4 16.6 1.2 17.0 15.7 16.4 1.1
O 15.4 10.7 12.4 0.0 15.2 11.2 12.6 0.0 15.6 12.3 13.7 0.5
N 11.9 6.8 9.2 0.6 11.8 7.5 9.6 0.4 12.4 9.4 10.9 0.3
D 8.5 3.8 6.1 0.1 8.7 4.5 6.5 -0.2 9.8 6.9 8.2 0.1
1999 21.0 3.6 11.9 1.2 20.0 4.3 11.7 1.0 18.1 6.1 11.8 1.1
Rainfall (mm)
Total Per Max ---------Number of days with---------------
Cent Fall >=0.2 Anomaly >=1.0 Anomaly >=5.0 Anomaly
J 95.2 166 15.1 23 5.8 18 6.1 9 4.2
F 29.0 74 7.3 13 0.4 9 0.6 1 -2.0
M 22.2 43 4.5 13 -2.3 9 -1.6 0 -3.9
A 43.1 94 9.6 13 -1.1 9 -1.1 4 0.6
M 55.7 103 20.6 12 -1.7 8 -2.3 4 0.4
J 88.6 168 30.5 12 0.5 8 -0.2 5 1.4
J 22.9 49 15.3 5 -5.9 4 -3.6 1 -1.8
A 109.4 190 48.8 13 0.6 9 0.4 7 3.6
S 77.4 134 15.4 19 7.5 14 5.3 6 2.2
O 53.9 89 11.0 13 -1.3 8 2.0 6 2.2
N 36.7 59 7.7 14 -1.0 9 -1.6 3 -1.4
D 108.5 170 18.1 25 8.8 19 7.8 7 1.8
1999 742.6 114 48.8 175 10.3 124 15.9 53 7.3
Sunshine (hours) Number of days with
Total Per 24hr Sunless days Gale Fog at 09h
Cent Max Total Anomaly Anomaly Anomaly
J 48.1 104 5.7 11 -3.0 0 -0.7 3 0.5
F 89.5 137 8.3 6 -3.5 0 -0.4 0 -2.0
M 112.1 106 10.7 2 -4.4 0 -0.4 0 -0.8
A 140.9 100 13.7 3 -0.4 0 0.0 0 -0.1
M 159.4 85 14.2 3 0.7 0 0.0 0 -0.1
J 202.6 106 14.5 3 0.9 0 0.0 0 -0.1
J 249.1 130 14.6 0 -1.7 0 0.0 0 -0.1
A 167.8 93 12.6 1 -1.2 0 0.0 0 -0.4
S 155.2 113 11.5 2 -0.9 0 0.0 0 -0.6
O 157.6 162 9.7 4 -2.8 0 -0.3 1 -1.9
N 73.9 122 6.8 8 -2.3 0 -0.2 0 -3.4
D 56.6 143 5.9 11 -4.0 0 -0.2 0 -2.2
1999 1612.8 112 14.6 54 -22.6 0 -2.4 4 -11.1
Number of days with
Snow falling 50% snow cover ---Hail----- Ice Pellets Thunder heard
at 09h
Anomaly Anomaly Anomaly Anomaly Anomaly
J 2 -1.6 0 -3.5 0 0.0 0 -0.3 0 -0.3
F 2 -1.4 1 -1.1 0 -0.2 2 1.6 0 -0.2
M 1 -1.7 0 -0.6 0 -0.5 0 -0.5 0 -0.5
A 1 1.0 0 -0.1 1 0.4 3 2.7 3 2.4
M 0 -0.1 0 0.0 1 0.7 1 0.9 2 0.2
J 0 0.0 0 0.0 0 -0.1 0 0.0 1 -1.3
J 0 0.0 0 0.0 0 -0.1 0 0.0 3 1.1
A 0 0.0 0 0.0 0 0.0 0 0.0 5 3.5
S 0 0.0 0 0.0 0 0.0 0 0.0 3 2.1
O 0 0.0 0 0.0 0 0.0 0 -0.1 1 0.7
N 0 -0.6 0 -0.1 0 -0.1 0 -0.1 0 -0.2
D 5 3.1 1 -0.5 1 0.9 0 -0.3 0 -0.2
1999 11 -2.3 2 -5.9 3 1.0 6 3.9 18 7.3
Air Pressure (millibar) Number of days with
Mean at 09h Air frost Ground frost
High Low Anomaly Anomaly Anomaly
J 1043.0 990.0 1013.6 -1.5 5 -6.5 18 0.2
F 1042.0 1002.0 1021.1 5.6 7 -3.0 14 -3.7
M 1032.0 984.0 1012.8 -2.2 5 -1.4 10 -5.5
A 1028.5 994.0 1014.9 -0.3 4 1.9 6 -3.2
M 1025.5 1007.0 1016.8 1.6 0 -0.2 0 -2.0
J 1027.5 999.0 1018.0 1.0 0 0.0 0 0.0
J 1030.0 1005.5 1018.2 0.7 0 0.0 0 0.0
A 1027.0 996.0 1013.4 3.1 0 0.0 0 0.0
S 1028.5 987.5 1009.6 -7.2 0 0.0 0 -0.3
O 1032.0 975.5 1015.1 -0.6 0 -0.6 0 -3.9
N 1040.5 994.0 1023.4 8.8 1 -4.6 5 -6.1
D 1030.0 980.0 1010.6 -4.4 8 -0.8 19 3.1
1999 1043.0 975.5 1015.6 -0.2 30 -15.2 72 -21.4
Number of hours with Piche evaporation (ml)
Rain falling Air frost Monthly Daily
Total Anomaly Total total Max
J 100.6 43.6 46.1 24.5 1.8
F 45.7 2.7 51.3 32.3 3.0
M 36.3 -20.7 15.6 40.0 3.2
A 44.0 -1.0 4.7 51.7 3.7
M 18.7 -27.3 0.0 71.5 5.0
J 49.9 8.9 0.0 65.9 4.2
J 6.3 -28.7 0.0 86.6 4.4
A 54.6 15.6 0.0 60.6 4.4
S 65.2 25.2 0.0 44.2 3.8
O 48.8 2.8 0.0 34.6 2.7
N 35.8 -17.2 0.2 32.0 2.0
D 70.5 11.5 55.2 26.4 1.9
1999 576.4 15.4 173.1 570.3 5.0
Number of days in 1999 when certain conditions observed at 07h
1999 1998 1997 1996 1996 1999 1998 1997 1996 1996
Cloud obscured 5 7 14 5 5 Wind N 42 32 24 44 43
8/8 cloud 105 150 144 147 139 NE 21 23 32 34 36
6/8 to 7/8 cloud 123 122 106 99 99 E 27 22 34 61 43
3/8 to 5/8 cloud 45 33 29 31 33 SE 11 13 23 26 31
1/8 to 2/8 cloud 44 28 40 45 36 S 38 41 51 47 36
Sky cloudless 43 25 32 39 53 SW 83 82 55 43 60
W 55 62 58 41 48
Visibility < 100m 0 0 0 0 0 NW 50 54 32 29 39
100-190m 2 1 4 2 1 calm 38 36 56 41 29
200-390m 2 3 8 2 6 force 1-3 298 308 285 290 309
400-900m 5 7 11 10 8 force 4-5 28 21 24 32 27
1.0-1.9km 25 19 17 19 13 force 6-7 1 0 0 3 0
2.0-3.9km 10 17 20 35 23 force 8-12 0 0 0 0 0
4-9km 56 62 73 73 78
10km or more 265 256 232 225 236
Highlights
January was a mild month with no days when the temperature stayed
below 0degC, and was the warmest since 1993. There were few air frosts
and just 2 days with snow, but rainfall was well above average.
February was a mild, dry and sunny month, with slightly less than
normal amounts of frost. There were, however some sharp ground frosts
between the 8th and 14th. After snowfall on the 8th, there was over 50
per cent ground snow cover on the 9th at 0900GMT (albeit only half a
centimetre deep). mean air pressure was substantially above average.
The month's minimum temperature of -4.8egC was the lowest in February
for 8 years.
March was another mild month, and quite dry too. After a cool spell
during the first week and a half, the temperature rose to 20.3degC
mid-month under anticyclonic conditions (the warmest March day for 9
years). The wettest day was the 2nd, but only 4.5mm fell.
April was another warmer than average month, but both rainfall and
sunshine totals were close to average. There was a cool spell around
mid-month, which as reflected in a steady decline in the soil
temperatures at all levels. Sleet fell briefly on the 13th, and about
two-thirds of the month's rainfall fell from the 19th to 25th.
May was mild, but duller than normal. While the rainfall total for the
month was slightly above average, this was largely due to a fall of
20.6mm (accompanied by 1cm diameter hail) during the evening of the
19th - a fall that lasted barely 50 minutes. The total duration of
rainfall during the month was well below normal.
June was wetter than normal while the average temperature was normal
for the first time this year. Almost all the month's rainfall fell in
two wet spells from the 1st-6th and 28th-30th, with 30.5mm falling
during a thunderstorm on the 2nd.
July was the warmest and driest since 1995 and the sunniest since
1990. Almost all the rain fell during the first 5 days of the month,
with a heavy thunderstorm during the night of the 2nd/3rd accounting
for two-thirds of the month's total in 90 minutes. The ground dried
out rapidly during the second half of the month, and it turned very
hot at times during the last week with 30.9degC on the 31st.
August was warm and wet. After a hot start (31.2degC on the 1st was
the hottest day of the year), there followed an unsettled and thundery
spell. 62mm of precipitation fell on the 8th and 9th, with the fall of
48.8mm on the 9th being the wettest day since September 1992. There
weere 5 days with thunder during August, which was generally dull
until the 19th - after when it turned drier and sunnier.
September was the warmest for 50 years, and the maximum temperature of
27.8C on the 11th was very high for so late in the year. It was also a
wet and sunny month, with the best of the sunshine during the first 10
days, and most of the rainfall coming in the second half of the month.
October was sunnier than September but, despite a lack of frost, was
cooler than average. There was remarkably little variation in the
daytime maximum temperatures throughout the month, and fog was less
frequent than normal.
November was a mild month, mainly due to a high average minimum
temperature that resulted from a low incidence of frost. In fact, air
frost occurred only on the 30th, lasting for about 10 minutes. It was
a dry and sunny month, due to persistent anticyclonic conditions -
mean air pressure was 8.8mb above normal.
December was a mild month overall, and both much wetter and sunnier
than normal. Although amounts snowfall amounts were small, the number
of days with snow falling (5) was much higher than in recent years,
and sleet on the 25th made it a white Christmas in Maidenhead. The
incidence of rainfall was high, as denoted by the fact that 0.2mm or
more fell on 25 days. A reading of -6.3degC on the 20th was the lowest
in any month since December 1991.
Overall, 1999 was a warm, wet and sunny year, with frequent
thunderstorms during the late spring and summer in Maidenhead. The
mean temperature was 0.2degC cooler than the warmest year on record in
the town, although only October was cooler than the long-term average.
There were 31 days during the year with afternoon temperatures
reaching 25degC or higher, but no days when it remained below freezing
all day.
While not as wet as 1998, the year was much wetter than normal with
wet months being interspersed throughout the year, and with some heavy
falls in thunderstorms. In fact 1999 was the wettest year (apart from
1998) since 1981.
The frequency of thunder was much higher in 1999 than normal, and the
year recorded the most thunderstorms in the town since 1982 (although
the same number of thundery days occurred in 1983 and 1984). Sunshine
was well-above average and, while the total for the year was not as
high as in 1995 and 1997, the number of sunless days was the lowest
since 1990. None of the months was outstandingly sunny in terms of
breaking any recent records (with the exception of October which was
the second sunniest in the last 40 years) although there were not
really any dull ones apart from May.
Frost, snow and fog all occurred less frequently that average,
although the number of days with snow was the greatest since 1996. The
number of days with fog (visibility below 1000 metres) at 0900GMT was
the lowest since 1967.
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Last updated 3 January 2000. This page is maintained by
brugge@met.reading.ac.uk
© 1999 Roger Brugge