October 2020

Temperatures
(all temperatures in degrees Celsius; all averages 1981 – 2010)

Mean daily maximum: 13.1
Difference from average: -0.2

Mean daily minimum: 6.2
Difference from average: –0.1

Mean air temperature: 9.6
Difference from average: -0.2

Absolute maximum: 17.1 (20th)

Absolute minimum: 1.1 (2nd)

Mean grass minimum: 4.3

Absolute grass minimum: -1.3 (2nd)

Mean concrete minimum: 4.3

Absolute concrete minimum: -0.9 (2nd)

Number of ground frosts: 2

Number of air frosts: 0

Mean soil temperature at 30cm depth: 11.5

Mean soil temperature at 100cm depth: 12.4

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

Total for the month: 96.6
Difference from average: +36.3

Percentage of the average: 160%

Wettest day: 26.8 (3rd)

Number of rain days (>0.2mm): 24

Number of wet days (=>1.0mm): 15

3-month total rainfall to 31st October: 264.4
Difference from average: +92.4

6-month rainfall total to 31st October: 420.6
Difference from average: +74.4

12-month rainfall total to 31st October: 710.6
Difference from average: +61.6

Sunshine
(all averages 1981 – 2010)

Total for the month: 69.8 hours
Difference from average: -32.3

Percentage of the average: 68%

Mean daily sunshine: 2.3 hours
Difference from average: -1.0

Sunniest day: 6.3 hours (8th)

Number of days with no recorded sunshine: 3

Cumulative sunshine since 1st January: 1434.0
Difference from average: +115.6

Note: 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
(all data from West Building roof, Lower Mountjoy)

Average wind speed: 4.9kph

Maximum gust: 67.6kph (13:15, 31st, W)

ISSN1350-483

Comments on October 2020
At 9.6°C, mean air temperature was 0.2°C below average, but nevertheless equal 52nd highest in 171 years. Both mean maximum and mean minimum were slightly below average. Maximum temperatures reached 10°C on all but two days; the maximum of 9.5°C on the 27th is the 434 coldest October day since 1900, easily into the lowest quartile. There were some mild days but nothing exceptional: the maximum of 17.1°C on the 20th is the equal 304th warmest October day since 1900, easily into the upper quartile. Perhaps of more interest is the minimum of 10.2°C the following night, the 338th warmest October night since 1900, but again not exceptional. This was a very brief, mild interlude in an otherwise very average month. There were just two ground frosts (2nd, 31st) but no air frosts.

Rainfall was well above average, the 31st wettest October since 1850. There was a notably high number of rain days (24), equal 11th highest in 171 years. The total of 26.8mm on the 3rd is the equal 28th highest for October (with 10th October 1896). The Met Office announced that Saturday 3rd October 2020 is now the wettest day on record since 1891 for UK-wide rainfall, the result of Storm Alex. It received the greatest rainfall in any single day averaged out across the UK, beating the previous record on the 25 August 1986 (which was caused by ex-hurricane Charley). Despite the dry spring, all running totals are now above average.

It was the 18th least sunny October since 1882 (with 1903). Only 2005 has been less sunny this century. There were three days without any sunshine recorded but this is a relatively low total compared earlier decades, with 16 days with no sun in October 1886 and October 1960; these Octobers rank 5th and 1st respectively in the list of least sunny Octobers at Durham.

Emeritus Professor Tim Burt
Department of Geography
Durham University