August 2025
SUMMARY OF THE METEOROLOGICAL READINGS AT DURHAM UNIVERSITY OBSERVATORY
August 2025
Temperatures (all temperatures in degrees Celsius; all averages 1991-2020)
Mean daily maximum: 21.9 Difference from average: +2.1
Mean daily minimum: 12.5 Difference from average: +1.2
Mean air temperature: 17.2 Difference from average: +1.6
Absolute maximum: 30.8 (13th)
Absolute minimum: 8.8 (17th)
Mean grass minimum: 11.0 Difference from average:
Absolute grass minimum: 6.8 (10th)
Mean concrete minimum: 11.7
Absolute concrete minimum: 5.3 (10th)
Number of ground frosts: 0 Difference from average: 0
Number of air frosts: 0 Difference from average:
Mean soil temperature at 300 mm depth: 18.2
Mean soil temperature at 1000 mm depth: 16.8
Rainfall (all totals in millimetres; all averages 1991-2020)
Total for the month: 23.6 Difference from average: -42.6
Percentage of the average: 35.7%
Wettest day: 6.4 (11th)
Number of rain days (>0.1 mm): 11 Difference from average: -5
Number of wet days (=>1.0 mm): 7
3-month total rainfall to 31st August 2025: 110.8 Difference from average: -78.6
6-month total rainfall to 31st August 2025: 159.0 Difference from average: -167.4
12-month total rainfall to 31st August 2025: 495.0 Difference from average: -186.0
Sunshine (all totals in hours; all averages 1991-2020)
Total for the month: 177.6 Difference from average: +11.0
Percentage of the average: 107%
Mean daily sunshine: 5.7 Difference from average: +0.4
Sunniest day: 11.4 (17th) Number of days with no recorded sunshine: 1
Note that the monthly sunshine total is now calculated from the UKMO E&NE regional total. Daily sunshine totals quoted here and in the data summary are uncorrected.
Wind (m/s; all data from the West Building roof, Lower Mountjoy campus)
Average wind speed: 1.49
Maximum gust: 24.1 (12th, 12:45, SW)
Pressure (mbar)
Average: 1014.0
Maximum: 1030.2 (16th, 09:15 – 09:45) Minimum: 991.9 (30th, 20:30)
Comments on August and Summer 2025
With a mean air temperature of 17.17 °C, this was the 5th hottest August at Durham since 1843; only 1947 (17.20 °C), 1975 (17.24 °C), 2022 (17.30 °C) and 1995 (17.59 °C) have been hotter. The 13th was the third hottest August day at Durham since 1843; only two August days in 1990 were hotter (2nd: 31.9 °C, 3rd: 32.5 °C). The second heatwave of the Durham summer happened from the 12th to the 15th inclusive (all days with a maximum of at least 25 °C). It was the 14th driest August at Durham since 1868, the driest since 2022 (13 mm). It was another sunny month, 29th sunniest in 145 years of record.
This has been the hottest summer on record at Durham: 16.92 °C, surpassing the previous record of 16.67 °C set in 2022. Based on the Eglise extension, one summer may have been even hotter than this one: 1826 (17.3 °C). The mean maximum temperature was the highest on record (21.63 °C), beating the previous 2022 record (21.53 °C), so too was the mean minimum (12.23 °C), beating the previous record from 2003 (11.97 °C) with 2022 close behind in third place (11.80 °C). As noted above, 13th August was a notably hot summer’s day, the equal 8th hottest summer day at Durham, but not close to the 19th July 2022 record holder (36.9 °C). There were two heatwaves, one in mid-July and one in mid-August. It was a dry summer, the 20th driest since 1850. Not surprisingly, it was also a sunny summer, the 22nd sunniest in 143 years.
Emeritus Professor Tim Burt
Department of Geography
Durham University