October 2019

Temperatures
(all temperatures in degrees Celsius; all averages 1961 – 1990)

Mean daily maximum: 12.0
Difference from average: -1.4

Mean daily minimum: 5.9
Difference from average: -0.4

Mean air temperature: 8.9
Difference from average: -0.9

Absolute maximum: 15.2 (11th)

Absolute minimum: 0.6 (28th)

Mean maximum the lowest since 1993

Mean grass minimum: 4.1

Absolute grass minimum: -1.7 (29th)

Mean concrete minimum: 5.1

Absolute concrete minimum: -0.3 (28th)

Number of ground frosts: 5

Number of air frosts: 0

Mean soil temperature at 30cm depth: 11.3

Mean soil temperature at 100cm depth: 12.6

Rainfall
(all totals in millimetres; all averages 1961 – 1990)

Total for the month: 88.4
Difference from average: +27.7

Percentage of the average: 146%

Wettest day: 14.4 (25th)

Number of rain days (>0.2mm): 18

Number of wet days (=>1.0mm): 14

3-month total rainfall to 31st October: 253.8
Difference from average: +81.8

6-month rainfall total to 31st October: 469.6
Difference from average: +123.4

12-month rainfall total to 31st October: 700.8
Difference from average: +51.8

Sunshine
(all averages 1961 – 1990)

Total for the month: 64.1 hours
Difference from average: -32.8

Percentage of the average: 66%

Mean daily sunshine: 2.1 hours
Difference from average: -1.1

Sunniest day: 7.3 hours (27th)

Number of days with no recorded sunshine: 5

Cumulative total sunshine since 1st January: 1259.7 hours
Difference from average: -151.4

Wind
(all data from West Building roof, Lower Mountjoy)

Average wind speed: 4.1kph

Maximum gust: 53.1kph (13:15, 27th, NW)

ISSN1350-483

Comments on October 2019
This was the coldest October at Durham since 2012; the October mean air temperature ranks 73rd since 1850 (n=170) so just below the median. The mean maximum was the lowest for October since 1993 and 25th lowest since 1900. Even so, there were only five ground frosts and no air frosts.

The rainfall total ranks 132nd in 170 years. It was the fifth month in a row with above-average rainfall and the third with a total above 80mm. It was largely a gloomy month, except for a few sunny days at the end of the month when anticyclonic conditions dominated, active fronts being well to the south over southern and south-western England. Overall it was the least sunny October since 2013, the 11th lowest since 1882*. 1960 has the lowest October sunshine total – only 40.9 hours.

Altogether a disappointing October, rather more what might be expected mid-autumn but rather unlike some of the mild Octobers recently experienced.

*In the course of writing this report, I was able to check the October 1905 sunshine total, which was given in my spreadsheet as just 9 hours. Using a newly available data file, I was able to check the results from 1905 – the total should have been 99 hours and has now been corrected. Clearly a simple typo – easily done!

Emeritus Professor Tim Burt
Department of Geography
Durham University