May 2023
SUMMARY OF THE METEOROLOGICAL READINGS AT DURHAM UNIVERSITY OBSERVATORY
May 2023
Temperatures (all temperatures in degrees Celsuis; all averages 1991-2020)
Mean daily maximum: 17.2 Difference from average: +1.8
Mean daily minimum: 7.4 Difference from average: +0.9
Mean air temperature: 12.3 Difference from average: +1.3
Absolute maximum: 21.2 (27th)
Absolute minimum: 2.7 (22nd)
Mean grass minimum: 5.7 Difference from average: +1.1
Absolute grass minimum: 0.4 (22nd)
Mean concrete minimum: 8.3
Absolute concrete minimum: 3.5 (29th)
Number of ground frosts: 0 Difference from average: -4
Number of air frosts: 0 Difference from average: -1
Mean soil temperature at 300 mm depth: 13.8
Mean soil temperature at 1000 mm depth: 11.7
Rainfall (all totals in millimetres; all averages 1991-2020)
Total for the month: 27.8 Difference from average: -16.7
Percentage of the average: 62%
Wettest day: 7.0 (8th)
Number of rain days (>0.1 mm): 10 Difference from average: -4
Number of wet days (=>1.0 mm): 8
3-month total rainfall to 31st May 2023: 130.6 Difference from average: -9.1
6-month total rainfall to 31st May 2023: 247.0 Difference from average: -92.3
12-month total rainfall to 31st May 2023: 641.6 Difference from average: -39.4
Sunshine (all totals in hours; all averages 1991-2020)
Total for the month: 186.7 Difference from average: -0.3
Percentage of the average: 100 %
Mean daily sunshine: 6.2 Difference from average: 0.2
Sunniest day: 10.3 (20th)
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 (kph; all data from the West Building roof, Lower Mountjoy campus)
Average wind speed: 4.7
Maximum gust: 40.2 (4th, 12:45, E)
Comments on May 2023
Like last month, there was a preponderance of winds from the north east in May. At 0900 GMT, four days experienced winds exactly from the north east, and in total 14 days saw winds at 0900 from the north-east quadrant (i.e. between north and east). May was a warm month, the sixth equal warmest May on record, with the seventh warmest mean maximum and the tenth warmest mean minimum. May was a relatively dry month, the 37th driest in 174 years, so well into the lowest quartile. No measurable rainfall was recorded in the last 13 days of the month. The number of hours of bright sunshine was almost exactly average; nevertheless, the cumulative amount of sunshine so far this year remains well above average.
With March and April both close to average temperature, and only June well above, even so this was the 13th warmest spring on record since 1844 (8.9 °C, 0.4 °C above average). It was the 87th driest spring in 174 years (130.6 mm) and the 53rd sunniest since 1882 (440.3 hours), 21 hours (95%) below average.
Emeritus Professor Tim Burt
Department of Geography
Durham University