December 2002

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

Mean daily maximum: 6.6
Difference from average: 0

Mean daily minimum: 3.4
Difference from average: +2.3

Mean air temperature: 5.0
Difference from average: +1.1

Absolute maximum: 11.1 (25th)

Absolute minimum: -4.1 (19th)

Mean grass minimum: 2.3

Absolute grass minimum: -4.5 (18th)

Number of ground frosts: 6

Number of air frosts: 5

Mean soil temperature at 30cm depth: 5.4

Mean soil temperature at 100cm depth: 7.8

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

Total for the month: 91
Difference from average: +33.6

Percentage of the average: 159%

Wettest day: 16.2 (30th)

Number of rain days (>0.25mm): 18

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

3-month total rainfall to 31st December 2002: 257.4
Difference from average: +85.5

6-month rainfall total to 31st December 2002: 458.8
Difference from average: +112

12-month rainfall total to 31st December 2002: 734.2
Difference from average: +85.2

Humidity
(Averages for 09:00 hours GMT)

Relative Humidity: 86%

Sunshine
(all averages 1961 – 1990)

Total for the month: 23.8 hours
Difference from average: -21.8

Percentage of the average: 52%

Mean daily sunshine: 0.8 hours
Difference from average: -0.7

Sunniest day: 5.8 hours (18th)

Number of days with no recorded sunshine: 15

Cumulative total sunshine since 1st January: 1182 hours
Difference from average: -147.3

Wind

The mean wind speed: 12.8 km/h [6.9kt]
Difference from average: -2.2 km/hr

The highest gust: 61 km/h [33kt] from 270° at 06:24 GMT on 2nd.

ISSN1350-483

Comments on December 2002
December was milder than normal because night-time temperatures were above average; daytime temperatures were exactly average for the month. The mean minimum was the highest since 1988. Mean air temperature ranked 123rd out of 154 and was the highest since 1994. It was a wet month, the wettest since 1990 and the 20th wettest December since 1852. Not surprisingly, there was very little bright sunshine, less than an hour per day. The total was the 2nd lowest on record (since 1950) and the lowest since 1978 when there was a meagre 9.7 hours for the whole month! As expected there were few air frosts and the number of ground frosts was equal lowest on record (with 1988) since 1961.

Professor Tim Burt
Department of Geography
Durham University