October 2012

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

Mean daily maximum: 12.3
Difference from average: -0.9

Mean daily minimum: 3.9
Difference from average: -2.4

Mean air temperature: 8.1
Difference from average: -1.7

Absolute maximum: 16.1 (21st)

Absolute minimum: -0.2 (26th)

Mean grass minimum: 1.5

Absolute grass minimum: -2.5 (10th)

Number of ground frosts: 14

Number of air frosts: 2

Mean soil temperature at 30cm depth: 11.2

Mean soil temperature at 100cm depth: 12.5

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

Total for the month: 83.4
Difference from average: +30.8

Percentage of the average: 159%

Wettest day: 19.0 (12th)

Number of rain days (>0.25mm): 20

Number of wet days (=> 1mm): 15

3-month total rainfall to 31st October: 309.6
Difference from average: +134.4

6-month rainfall total to 31st October: 610.6
Difference from average: +280.3

12-month rainfall total to 31st October: 885
Difference from average: +235

Humidity
(Averages for 09:00 hours GMT)

Relative Humidity: 89%

Sunshine
(all averages 1961 – 1990)

Total for the month: 108.6 hours
Difference from average: +15.5

Percentage of the average: 117%

Mean daily sunshine: 3.5 hours
Difference from average: +0.5

Sunniest day: 8.3 hours (7th)

Number of days with no recorded sunshine: 1

Cumulative total sunshine since 1st January: 1098.2 hours
Difference from average: -119.3

ISSN1350-483

Comments on October 2012
October was a cold month: the mean air temperature was the equal 28th coldest since 1850 and the coldest since 1993. Mean maximum was equal 30th lowest since 1900 and also the coolest since 1993. The mean minimum was more extreme: 9th lowest since 1900 and the lowest since 1992. The absolute maximum was disappointing at only 16.1°C, again the lowest since 1993. There was the highest number of ground frosts since 1981.

It was the wettest October since 2004 with the most rain days since 2006. As might be expected the period totals remain very extreme: the 32nd wettest of any 3-month period since 1850; the 2nd wettest 6-month period, only exceeded by the previous 6 months (i.e. April-September 2012); and the 38th wettest of any 12-month period (n=1943). Not surprisingly, it has been the wettest 7-month period in Durham since records began. The total for 2012 is already 808.8mm – already the 8th wettest year on record even if we get no rain at all in November or December!

Professor Tim Burt
Department of Geography
Durham University