February 2023
SUMMARY OF THE METEOROLOGICAL READINGS AT DURHAM UNIVERSITY OBSERVATORY
February 2023
Temperatures (all temperatures in degrees Celsius; all averages 1991-2020)
Mean daily maximum: 10.0 Difference from average: +2.3
Mean daily minimum: 3.5 Difference from average: +2.1
Mean air temperature: 6.7 Difference from average: +2.2
Absolute maximum: 15.7 (20th)
Absolute minimum: -2.0 (14th)
Mean grass minimum: 2.0 Difference from average: +2.6
Absolute grass minimum: -4.2 (14th)
Mean concrete minimum: 2.0
Absolute concrete minimum: -3.5 (14th)
Number of ground frosts: 8 Difference from average: -8
Number of air frosts: 4 Difference from average: -6
Mean soil temperature at 300 mm depth: 6.2
Mean soil temperature at 1000 mm depth: 6.8
Rainfall (all totals in millimetres; all averages 1991-2020)
Total for the month: 19.6 Difference from average: -25.7
Percentage of the average: 43%
Wettest day: 5.4 (28th)
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 28th February 2022: 116.4 Difference from average: -43.1
6-month total rainfall to 28th February 2022: 409.0 Difference from average: 54.3
12-month total rainfall to 28th February 2022: 630.2 Difference from average: -50.8
Sunshine (all totals in hours; all averages 1991-2020)
Total for the month: 88.4 Difference from average: +3.1
Percentage of the average: 104%
Mean daily sunshine: 3.2 Difference from average: +0.1
Sunniest day: 7.9 (13th)
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 (kph; all data from the West Building roof, Lower Mountjoy campus)
Average wind speed: 7.6
Maximum gust: 91.7 (17th, 10:45, WNW)
Comments on February 2023
Altogether, February was a remarkably mild month, the 2nd warmest on record since 1844, surpassed only in 1998 (7.6 °C). Both the mean maximum and the mean minimum are 3rd highest on record. The mean maximum has only been exceeded in 1998 and 2019; the mean minimum only in 1846 and 1998. The maximum temperature (15.7 °C) on the 20th is the sixth warmest February day on record; the minimum temperature (9.0 °C) on the 2nd is the 28th warmest February night. 2023 is one of nine Februarys to have had only four air frosts since 1850; six Februarys have had just three air frosts with three having just two, including last year. There was the equal 2nd lowest total number of ground frosts since 1874.
It was a relatively dry month, the 34th lowest total for February since 1850. There was no measurable precipitation at all in the first half of the month. The wettest day of the month (31st) saw a total of only 5.4 mm. Sunshine was just a little above the 1991-2020 average but nevertheless the 31st highest February total since 1881.
For the winter as a whole, despite a below-average December, this was the 15th mildest winter (mean air temperature: 5.0 C) on record at Durham since 1844, although not as warm as the previous winter (5.4 °C) which ranks equal 4th warmest. There were 27 air frosts, 9 more than last year, but only 36 ground frosts, 16 below average, the sixth lowest total since 1874, and 7 fewer than last year. It was a relatively dry winter (116.4 mm), 73% of normal, ranking 58th driest out of a total of 173 winters. The winter was sunnier than normal (250 hours, 122%) compared to the 1991-2020 average. Nevertheless, it still ranks 5th overall since 1880, just slightly less sunny than the previous winter (254 hours) which ranks 4th. These two sunny winters show just how much the clarity of the atmosphere has improved compared to most of the record given significant reductions in the concentration of particulate matter in the air.
Emeritus Professor Tim Burt
Department of Geography
Durham University