December 2006

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

Mean daily maximum: 7.7
Difference from average: +1.1

Mean daily minimum: 2.2
Difference from average: +1.1

Mean air temperature: 5.0
Difference from average: +1.1

Absolute maximum: 12.9 (13th)

Absolute minimum: -4.7 (20th)

Mean grass minimum: -0.4

Absolute grass minimum: -8.1 (20th)

Number of ground frosts: 17

Number of air frosts: 9

Mean soil temperature at 30cm depth: 6.3

Mean soil temperature at 100cm depth: 8.7

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

Total for the month: 97
Difference from average: +39.6

Percentage of the average: 169%

Wettest day: 24.2 (11th)

Number of rain days (>0.25mm): 20

Number of wet days (=> 1mm): 16

3-month total rainfall to 31st December: 241
Difference from average: +69

6-month rainfall total to 31st December: 339
Difference from average: -7.2

12-month rainfall total to 31st December: 588.7
Difference from average: -60.3

Humidity
(Averages for 09:00 hours GMT)

Relative Humidity: 86.3%

Sunshine
(all averages 1961 – 1990)

Total for the month: 72.4 hours
Difference from average: +26.8

Percentage of the average: 158.7%

Mean daily sunshine: 2.3 hours
Difference from average: +0.8

Sunniest day: 5.9 hours (5th)

Number of days with no recorded sunshine: 11

Cumulative total sunshine since 1st January: 1365.3 hours
Difference from average: +36.1

Wind

The mean wind speed: 14.4km/h [7.8kt]
Difference from average: -0.8km/hr

The highest gust: 114.8km/h [62kt] from 201° at 19:07 GMT on 12th

ISSN1350-483

Comments on December 2006
Despite some cold days over the Christmas period (which were also very dull), there were milder days in the first half of the month and at the end, so that it ended up well above average temperature. Overall, all three measure of temperature were 1.1°C above average. It was the warmest December since 1997 but (with 2004 and 2002) only ranks 32nd warmest since 1850.

It was a wet month with well above average rainfall, the 17th wettest December since 1852. The fall of 24.2mm on the 11th was the wettest day of the year. Despite the rainfall, it was the 6th sunniest December since 1882, but 2003 and 2004 were both sunnier. In the week from the 22nd to the 28th, only the 27th recorded any bright sunshine at all (1.1 hour). Although there were strong winds on New Year’s Eve, the strongest gust was on the 12th at 114kph.

Professor Tim Burt
Department of Geography
Durham University