Observations up to 0900 GMT on 18 September 2020 are included in the table.

If the date above does not match today's date, then there are still observations to be added to the database. This will apply particularly at weekends or when the University is closed.

Anomalies refer to the "month so far" for the current month, otherwise to whole-month averages - in all cases using data for the period 1981-2010.

Note that the mean temperature (and its anomaly) will, until the end of the month, refer to the average of the mean maximum and mean minimum temperatures applicable up to the day before that shown above - and therefore may not agree exactly with the mean maximum and mean minimum values shown in the table.

Year	2020	2020	2020	2020
Month	September	August	July	June
Number of days with data used	18	31	31	30
Average air temperature (C)	16.0	19.1	17.1	16.2
Difference from average (degC)	+0.8	+1.8	-0.4	+0.9
Average daily maximum temperature (C)	21.4	23.8	22.2	21.0
Difference from average (degC)	+1.8	+1.7	-0.2	+1.0
Highest air temperature (C)	27.9	35.0	35.7	31.4
Average daily minimum temperature (C)	10.4	14.3	12.1	11.3
Difference from average (degC)	-0.3	+1.8	-0.6	+0.7
Lowest air temperature (C)	4.4	6.6	6.9	6.2
Air frosts (days)	0	0	0	0
Difference from average (days)	0.0	0.0	0.0	0.0
Lowest grass minimum temperature (C)	-4.3	-0.8	-1.0	-1.9
Ground frosts (days)	6	1	3	1
Difference from average (days)	+3.9	+0.5	+2.7	-1.1
Precipitation total (mm)	2.4	95.2	32.0	69.5
Percentage of average	7	182	69	155
Greatest 24-hour total (mm)	1.5	28.3	8.8	17.8
Rain days (0.2 mm or more) (days)	3	14	13	16
Difference from average (days)	-3.5	+2.8	+1.7	+5.2
Electronic sunshine total (KZ recorder) (h)	116.7	196.0	220.8	218.3
Sunshine total (C/S recorder) (h)	99.8	205.7	211.7	205.4
Percentage of average	120	107	107	108
Greatest daily total (h)	10.5	13.2	14.5	14.6
Number of sunless days	1	3	1	2
Difference from average (days)	-0.6	+1.7	-0.3	+0.3
Average daily solar irradiance (MJ/m2)	13.3	14.9	18.3	18.4
Difference from average (MJ/m2)	+1.8	0.0	+0.9	+0.2
Highest daily total (MJ/m2)	17.54	23.66	28.46	29.95
Average mean sea level pressure (mb)	1021.9	1012.9	1017.1	1012.8
Difference from average (mb)	+5.6	-3.2	+0.7	-4.2
Average 10 cm soil temperature (C)	16.1	19.7	19.3	18.3
Difference from average (degC)	+1.0	+2.0	+0.8	+1.5
Average 30 cm soil temperature (C)	16.7	19.0	17.9	17.2
Difference from average (degC)	+0.9	+1.4	+0.4	+1.6
Average 100 cm soil temperature (C)	16.6	17.5	16.3	14.9
Difference from average (degC)	+0.8	+1.0	+0.6	+1.1
Days with snow/sleet falling	0	0	0	0
Difference from average (days)	0.0	0.0	0.0	0.0
Days with 50% snow cover at 0900 GMT	0	0	0	0
Difference from average (days)	0.0	0.0	0.0	0.0
Days with thunder heard	0	4	0	3
Difference from average (days)	-0.5	+2.4	-1.5	+1.8
Days with fog at 0900 GMT	0	0	0	0
Difference from average (days)	-0.4	-0.2	-0.1	-0.1