August 2015

Temperatures
(all temperatures in degrees Celsius; all averages 1961 – 1990)

Mean daily maximum: 18.9
Difference from average: -0.2

Mean daily minimum: 11.3
Difference from average: +0.9

Mean air temperature: 15.1
Difference from average: +0.4

Absolute maximum: 22.6 (21st)

Absolute minimum: 6.3 (16th)

Mean grass minimum: 9.4

Absolute grass minimum: 4.6 (16th)

Number of ground frosts: 0

Number of air frosts: 0

Mean soil temperature at 30cm depth: 16.2

Mean soil temperature at 100cm depth: 14.8

Rainfall
(all totals in millimetres; all averages 1961 – 1990)

Total for the month: 81.6
Difference from average: +14.5

Percentage of the average: 122%

Wettest day: 17.6 (14th)

Number of rain days (>0.25mm): 14

Number of wet days (=> 1mm): 11

3-month total rainfall to 31st August: 203.6
Difference from average: +31.6

6-month rainfall total to 31st August: 343.7
Difference from average: -2.5

12-month rainfall total to 31st August: 560.8
Difference from average: -88.2

Humidity
(averages for 09:00 hours GMT)

Relative Humidity: 79%

Sunshine
(all averages 1961 – 1990)

Total for the month: 126.5 hours
Difference from average: -29.0

Percentage of the average: 81%

Mean daily sunshine: 4.1 hours
Difference from average: -0.9

Sunniest day: 9.5 hours (23rd)

Number of days with no recorded sunshine: 3

Cumulative total sunshine since 1st January: 1020.6 hours
Difference from average: +20.1

ISSN1350-483

Comments on August 2015
August was a disappointing month. Night-time temperatures were well above average but daytime- temperatures below average. The mean maximum was equal 51st lowest since 1900 (n=116), but the mean minimum was equal 95th highest. Overall, the mean air temperature was equal 108th (n=166) highest, just slightly above average. Rainfall was just above average, with almost half the days recording at least 0.25mm. There was only 81% of the average number of hours of bright sunshine, sadly only just over half the record-breaking total in 1995.

For the summer as a whole, it was the coldest summer (13.9°C) since 1987 (equal to 1993). It was the 110th wettest summer in 166 years (203.6mm) and, perhaps most telling of all, there was the 17th lowest amount of bright sunshine (386.1 hours) since 1882. A combined index of summer weather shows this to be the 32nd worst summer at Durham since 1882: roughly a quarter will be worse than 2015 but three quarters will be better!

Professor Tim Burt
Department of Geography
Durham University