October 2023
SUMMARY OF THE METEOROLOGICAL READINGS AT DURHAM UNIVERSITY OBSERVATORY
October 2023
Temperatures (all temperatures in degrees Celsuis; all averages 1991-2020)
Mean daily maximum: 13.9 Difference from average: +0.4
Mean daily minimum: 7.5 Difference from average: +1.0
Mean air temperature: 10.7 Difference from average: +0.7
Absolute maximum: 20.4 (1st)
Absolute minimum: -1.7 (17th)
Mean grass minimum: 6.3 Difference from average: +1.8
Absolute grass minimum: -3.9 (17th)
Mean concrete minimum: 7.5
Absolute concrete minimum: -1.6 (23rd)
Number of ground frosts: 4 Difference from average: -1
Number of air frosts: 1 Difference from average: 0
Mean soil temperature at 300 mm depth: 13.1
Mean soil temperature at 1000 mm depth: 13.9
Rainfall (all totals in millimetres; all averages 1991-2020)
Total for the month: 146.8 Difference from average: +83.1
Percentage of the average: 230%
Wettest day: 35.2 (20th)
Number of rain days (>0.1 mm): 22 Difference from average: +4
Number of wet days (=>1.0 mm): 15
3-month total rainfall to 31st October 2023: 282.8 Difference from average: +96.2
6-month total rainfall to 31st October 2023: 474.6 Difference from average: 120.3
12-month total rainfall to 31st October 2023: 797.8 Difference from average: +116.8
Sunshine (all totals in hours; all averages 1991-2020)
Total for the month: 75.4 Difference from average: -23.2
Percentage of the average: 76%
Mean daily sunshine: 2.5 Difference from average: -0.7
Sunniest day: 8.7 (12th)
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: 5.9
Maximum gust: 85.3 (20th, 12:30, E)
Comments on October 2023
Like September, October started unusually mild but, of course, it cooled off steadily through the month with a maximum below 10 °C by the 20th (9.4 °C). Even so, overall, it was an above-average month for temperature, night-time temperatures more so than daytime temperatures. The mean air temperature (10.69 °C) is the 24th highest on record for October since 1844 (n=181), but it was more than a degree cooler than 2022 (11.78 °C), and overall nine Octobers have been warmer this century. Soil temperatures remain relatively high; there were only 4 ground frosts and one air frost.
It was a very wet month, the fourth wettest October on record since 1868 (fifth wettest since 1850 if we include 160.2 mm in October 1865, during a period of some uncertainty about the Durham rainfall observations). Only 1903 (201.8), 1960 (172.5 mm) and 1896 (148.8 mm) have had wetter Octobers in Durham since 1868. The total of 22 rain days is the equal 21st highest on record, not exceptionally high, implying that rain per rain day was very high this month; indeed, the rain per rain day of 6.7 mm/day is the 7th equal highest for October on record since 1868. The total of 35.2 mm on the 20th is the 10th highest daily total on record for October. Not surprisingly, it was a dull month, well below average for hours of bright sunshine, the 32nd lowest total since 1880 (n=143).
There was an very high gust of wind of 85.3 kph just after noon on the 20th.
Emeritus Professor Tim Burt
Department of Geography
Durham University