April 2023
SUMMARY OF THE METEOROLOGICAL READINGS AT DURHAM UNIVERSITY OBSERVATORY
April 2023
Temperatures (all temperatures in degrees Celsuis; all averages 1991-2020)
Mean daily maximum: 12.0 Difference from average: -0.5
Mean daily minimum: 4.1 Difference from average: +0.1
Mean air temperature: 8.0 Difference from average: -0.2
Absolute maximum: 15.1 (30th)
Absolute minimum: -1.8 (3rd)
Mean grass minimum: 2.6 Difference from average: +0.7
Absolute grass minimum: -4.1 (3rd)
Mean concrete minimum: 4.0
Absolute concrete minimum: -2.5 (3rd)
Number of ground frosts: 8 Difference from average: -2
Number of air frosts: 2 Difference from average: -1
Mean soil temperature at 300 mm depth: 10.1
Mean soil temperature at 1000 mm depth: 9.2
Rainfall (all totals in millimetres; all averages 1991-2020)
Total for the month: 50.0 Difference from average: -1.2
Percentage of the average: 98%
Wettest day: 10.2 (21st)
Number of rain days (>0.1 mm): 18 Difference from average: +4
Number of wet days (=>1.0 mm): 13
3-month total rainfall to 30th April 2023: 122.4 Difference from average: -17.3
6-month total rainfall to 30th April 2023: 323.2 Difference from average: -16.1
12-month total rainfall to 30th April 2023: 665 Difference from average: -17.3
Sunshine (all totals in hours; all averages 1991-2020)
Total for the month: 156.4 Difference from average: +2.1
Percentage of the average: 101%
Mean daily sunshine: 5.2 Difference from average: 0.1
Sunniest day: 10.9 (3rd)
Number of days with no recorded sunshine: 2
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: 5.3
Maximum gust: 56.3 (11th, 23:15, S)
Comments on April 2023
This was very much an ‘average’ month with mean air temperature, precipitation total and total hours of bright sunshine all very close to the 1991-2020 average. This was only the second month since September 2021 to experience below-average temperature. Nevertheless, it ranks as the 40th warmest April in 180 years of record. The absolute temperature range (16.9 °C) was remarkably small, equal 18th lowest since 1844, equal to that in April 2001 and the lowest since April 1986 (15.9 °C). The absolute maximum is the lowest for April since 2001 (14.8 °C) and the 22nd lowest since 1844. This was the 117th wettest April since 1850, 12.7 mm above the median value. Only 24 Aprils have had fewer air frosts since 1844.
Emeritus Professor Tim Burt
Department of Geography
Durham University