September 2026
SUMMARY OF THE METEOROLOGICAL READINGS AT DURHAM UNIVERSITY OBSERVATORY
September 2026
Temperatures (all temperatures in degrees Celsius; all averages 1991-2020)
Mean daily maximum: 19.5 Difference from average: +2.2
Mean daily minimum: 10.6 Difference from average: +1.4
Mean air temperature: 15.1 Difference from average: +1.8
Absolute maximum: 24.9 (22nd)
Absolute minimum: 3.0 (29th)
Mean grass minimum: 8.7 Difference from average: +1.6
Absolute grass minimum: 0.2 (29th)
Mean concrete minimum: 10.0
Absolute concrete minimum: 3.0 (29th)
Number of ground frosts: 0 Difference from average: -1
Number of air frosts: 0 Difference from average: 0
Mean soil temperature at 300 mm depth: 16.0
Mean soil temperature at 1000 mm depth: 15.8
Rainfall (all totals in millimetres; all averages 1991-2020)
Total for the month: 16.6 Difference from average: -40.2
Percentage of the average: 29.2 %
Wettest day: 4.2 (22nd)
Number of rain days (>0.1 mm): 14 Difference from average: -1
Number of wet days (=>1.0 mm): 6 Difference from average: -4
3-month total rainfall to 30th September 2026: 63.4 Difference from average: -121.6
6-month total rainfall to 30th September 2026: 212.6 Difference from average: -129.2
12-month total rainfall to 30th September 2026: 631.4 Difference from average: -48.8
Sunshine (all totals in hours; all averages 1991-2020)
Total for the month: 145.7 Difference from average: +13.6
Percentage of the average: 110.3 %
Mean daily sunshine: 4.7 Difference from average: +0.3
Sunniest day: 8.3 (15th) Number of days with no recorded sunshine: 0
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; data from the West Building roof, Lower Mountjoy campus)
Average wind speed: 1.7
Maximum gust: 21.0 (4th, 13:15, WSW)
Pressure (mbar; data from the West Building roof, Lower Mountjoy campus)
Average: 1014.4
Maximum: 1001.1 (8th, 15:15) Minimum: 1029.9 (21st, 08:00)
Comments on September 2026
Both the mean air temperature (15.1 °C) and the mean daily maximum temperature (19.5 °C) are the 6th highest on record for September, the warmest September since 2023. The mean daily minimum temperature is the 8th highest on record. The mean grass minimum is also the 8th highest on record. The minimum air temperature on the 155h (16.0 °C) is the 9th equal highest minimum for September since 1850. The minimum air temperature of 15.6 °C on the 3rd is the equal 16th highest for September (n=5310). 2026 has seen the warmest average temperature for the first nine months of the year since 1844 (11.6 °C), surpassing the previous record in 2022 (11.5 °C).
It was the 16th driest September on record, the driest September at Durham since 2014. Sunshine was just a little above average.
Emeritus Professor Tim Burt
Department of Geography
Durham University