May 2026

SUMMARY OF THE METEOROLOGICAL READINGS AT DURHAM UNIVERSITY OBSERVATORY

Temperatures (all temperatures in degrees Celsuis; all averages 1991-2020)

Mean daily maximum: 16.9 Difference from average: +1.5

Mean daily minimum: 7.2 Difference from average: +0.7

Mean air temperature: 12.1 Difference from average: +1.0

Absolute maximum: 29.7 (25^th)

Absolute minimum: 0.3 (6^th)

Mean grass minimum: 4.9 Difference from average: +0.3

Absolute grass minimum: -2.4 (6^th)

Mean concrete minimum: 7.8

Absolute concrete minimum: 0.9 (6^th)

Number of ground frosts: 6 Difference from average: +2

Number of air frosts: 0 Difference from average: -1

Mean soil temperature at 300 mm depth:

Mean soil temperature at 1000 mm depth:

Rainfall (all totals in millimetres; all averages 1991-2020)

Total for the month: 88.8 Difference from average: +44.3

Percentage of the average: 199.6

Wettest day: 27.2 (2^nd)

Number of rain days (>0.1 mm): 18 Difference from average: +4

Number of wet days (=>1.0 mm): 12 Difference from average: +3

3-month total rainfall to 2026 31^st May 2026: 154.6 Difference from average: +14.9

6-month total rainfall to 31^st May 2026: 346.0 Difference from average: +6.7

12-month total rainfall to 31^st May 2026: 719.8 Difference from average: +39.6

Sunshine (all totals in hours; all averages 1991-2020)

Total for the month: 224.3 Difference from average: +37.3

Percentage of the average: 119.6%

Mean daily sunshine: 7.2 Difference from average: +1.2

Sunniest day: 12.4 (25^th) 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: 1.5

Maximum gust: 14.3 (11^th, 01:30,WNW; 12^th, 17:15, NE)

Pressure (mbar; data from the West Building roof, Lower Mountjoy campus)

Average: 1015.1

Maximum: 1030.4 (27^th, 08:15 – 08:45) Minimum: 997.6 (13^th, 07:30)

Comments on May and Spring 2026

After a warm May Day (maximum temperature 22.5 °C), temperatures in May were disappointing for the first part of the month and did not exceed 20 °C again until the 23^rd (maximum 24.5 °C). On the 25^th, Durham experienced its hottest May Day on record: 29.7 °C, surpassing the previous May record: 29.0 °C on 23^rd May 2001, and there was the second warmest May night ever (14.5 °C). Notwithstanding the cool start, this was still the 12^th warmest May on record.

It was a wet month, 166^th wettest in 177 years. The 2^nd was the equal wettest May day since 1850. It was nevertheless a sunny month, the 10^th sunniest May at Durham since 1881, according to the calculation using the Met Office E & NE regional data; however, this may not reflect conditions close to the North Sea coast.

Continuing trends this decade, spring 2026 was the 6^th warmest spring on record since 1844. It was a wet spring but not exceptionally so, total 154mm, 17.2 mm above average. It was a very sunny spring, the third sunniest on record at Durham (598.4 hours, 130% of average).

Emeritus Professor Tim Burt

Department of Geography

Durham University

[email protected]