November 2021

SUMMARY OF THE METEOROLOGICAL READINGS AT DURHAM UNIVERSITY OBSERVATORY

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

Mean daily maximum: 11.0 Difference from average: +1.4
Mean daily minimum: 4.7 Difference from average: +1.1
Mean air temperature: 7.9 Difference from average: +1.3
Absolute maximum: 15.9 (9th)
Absolute minimum: -2.1 (28th)
Mean grass minimum: 3.0
Absolute grass minimum: -5.5 (28th)
Mean concrete minimum: -3.2
Absolute concrete minimum: -4.1 (28th)
Number of ground frosts: 5
Number of air frosts: 3
Mean soil temperature at 300 mm depth: 9.5
Mean soil temperature at 1000 mm depth: 11.3

Rainfall (all totals in millimetres; all averages 1981-2010)

Total for the month: 51.0 Difference from average: -23.8
Percentage of the average: 68%
Wettest day: 26.4 (26th)
Number of rain days (>0.1 mm): 14
Number of wet days (=>1.0 mm): 5
3-month total rainfall to 30th November 2021: 183.4 Difference from average: +11.4
6-month total rainfall to 30th November 2021: 326.0 Difference from average: -20.2
12-month total rainfall to 30th November 2021: 779.2 Difference from average: +130.2

Sunshine (all totals in hours; all averages 1981-2010)

Total for the month: 78.3 Difference from average: +10.3
Percentage of the average: 115%
Mean daily sunshine: 2.5 Difference from average: +0.3
Sunniest day: 6.2 (22nd)
Number of days with no recorded sunshine: 1
Cumulative sunshine since 1st January: 1436.1 Difference from average: +22.3

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: 6.1
Maximum gust: 90.1 (27th, NE, 01:15)

Comments on November 2021

This was the 6th warmest November at Durham since 1843. For most of the month, it looked like ranking even higher, but a couple of quite cold days near the end of the month, following the passage of Strom Arwen, brought the average down. The maximum of 2.55 °C on the 28th is the 85th lowest November maximum since 1900 (n = 3660). The mean maximum was the equal 7th highest on record, and the mean minimum was the equal 13th highest. There were only 5 ground frosts, the equal 6th lowest total since 1874, but one more than last year. The number of air frosts (3) is the equal 25th lowest total, again one more than in November 2020!

The total rainfall of 51 mm is the 64th lowest total since 1850. It would have been a much drier month but for Storm Arwen: 26.4 mm was recorded on the 26th; most of the rain fell between 2000 on the 26th and 0400 on the 27th. The number of rain days (14) was relatively low: the equal 35th lowest total on record. Given the relatively low number of rain days, it is not surprising that sunshine was a little above average, the 20th sunniest November since 1881.

The maximum gust associated with Storm Arwen was at 01:15 on the 27th: 90.1 kph with winds from the NE. The passage of the cold front saw a drop in temperature from 4.9 °C at 0:06 to 0.6 °C at 00:50.

This was the 2nd mildest autumn on record at Durham (11.6 °C), exceeded only in 2006 (12.0 °C). The mean maximum (15.0 C) is also the 2nd highest on record, while the mean minimum is the equal 2nd highest on record (8.1 °C, with 1857 and 2011); in both cases, 2006 again holds the record. There was the equal 11th lowest total of air frosts (3); only autumn 1984 has recorded no air frosts since 1850. There was the equal second lowest number of ground frosts (6, with 1984); only autumn 2011 has had fewer (4). Autumn rainfall (183.4 mm) was 94% of average, ranking 96th in a series of 172 years. The autumn sunshine total (305.3 hours) is just into the upper quartile for sunshine data since 1880, ranking 106th in a series of 142 years.

Emeritus Professor Tim Burt
Department of Geography
Durham University

[email protected]