November 2009

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

Mean daily maximum: 10.5
Difference from average: +1.8

Mean daily minimum: 4.4
Difference from average: +1.6

Mean air temperature: 7.5
Difference from average: +1.8

Absolute maximum: 14.5 (19th)

Absolute minimum: 0.2 (30th)

Mean grass minimum: 1.4

Absolute grass minimum: -2.6 (30th)

Number of ground frosts: 12

Number of air frosts: 0

Mean soil temperature at 30cm depth: 8.6

Mean soil temperature at 100cm depth: 10.5

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

Total for the month: 153.8
Difference from average: +91.8

Percentage of the average: 248%

Wettest day: 27.2 (29th)

Number of rain days (>0.25mm): 22

Number of wet days (=> 1mm): 18

3-month total rainfall to 30th November: 207.2
Difference from average: +37.1

6-month rainfall total to 30th November: 494.4
Difference from average: +153.9

12-month rainfall total to 30th November: 722.5
Difference from average: +73.5

Humidity
(Averages for 09:00 hours GMT)

Relative Humidity: 89%

Sunshine
(all averages 1961 – 1990)

Total for the month: 73.8 hours
Difference from average: +7.7

Percentage of the average: 112%

Mean daily sunshine: 2.5 hours
Difference from average: +0.3

Sunniest day: 5.8 hours (17th)

Number of days with no recorded sunshine: 2

Cumulative total sunshine since 1st January: 1312.9 hours
Difference from average: +29.3

Wind

The mean wind speed: 10.7km/h [5.8kt]
Difference from average: -3.4km/hr

The highest gust: 92.8km/h [50.1kt] from 188° at 13:04 GMT on 25th

ISSN1350-483

Comments on November 2009
This was the 11th equal warmest November on record since 1850. 2001 and 2003 were equally warm, 2006 was warmer! Daytime temperatures reached double figures on no less than 17 days and there were no ground frosts, even on the seemingly “very cold” nights at the end of the month.

This was also the 2nd wettest November since 1850, only exceeded by November 1965 when a total of 185.9mm was recorded. Indeed, this was the 24th highest month total for all months since January 1850 (n = 1919), so only about 1% of months are this wet in Durham.  Nevertheless, compared to July, no one day contributed the majority; there were falls over 25mm on 1st (26mm) and 29th (27.2mm). In all, there were 22 rain days (>0.25mm) and 18 wet days (>1mm). Not surprisingly, all long-term totals are now above average again, most notably the 6-month total. And despite all the rain, sunshine was just a little above average.

So, mild and wet summarises November 2009 very nicely!

Professor Tim Burt
Department of Geography
Durham University