December 2003

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

Mean daily maximum: 7.9
Difference from average: +1.3

Mean daily minimum: 0.9
Difference from average: -0.2

Mean air temperature: 4.4
Difference from average: +0.5

Absolute maximum: 12.8 (6th)

Absolute minimum: -8.1 (31st)

Mean grass minimum: -0.5

Absolute grass minimum: -8.2 (31st)

Number of ground frosts: 17

Number of air frosts: 14

Mean soil temperature at 30cm depth: 4.8

Mean soil temperature at 100cm depth: 7.6

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

Total for the month: 67.2
Difference from average: -9.8

Percentage of the average: 117%

Wettest day: 23 (2nd)

Number of rain days (>0.25 mm): 16

Number of wet days (=> 1 mm): 11

3-month total rainfall to 30th November 2003: 116.4
Difference from average: -55.5

6-month rainfall total to 30th November 2003: 236
Difference from average: -120.4

12-month rainfall total to 30th November 2003: 408.8
Difference from average: -240.2

Humidity
(Averages for 09:00 hours GMT)

Relative Humidity: 85.3%

Sunshine
(all averages 1961 – 1990)

Total for the month: 73.7 hours
Difference from average: +28.1

Percentage of the average: 161%

Mean daily sunshine: 2.4 hours
Difference from average: +0.9

Sunniest day: 5.9 hours (7th)

Number of days with no recorded sunshine: 9

Cumulative total sunshine since 1st January: 1492.8 hours
Difference from average: +163.5

Wind

The mean wind speed: 13.7km/h [7.4kt]
Difference from average: -1.3km/hr

The highest gust: 75.9km/h [41kt] from 285° at 20:28 GMT on 13th.

ISSN1350-483

Comments on December 2003
For the 10th time in 12 months, mean air temperature was above average, although only modestly so: December 2003 ranks only 104th out of 154. Mean maximum temperature was somewhat above average (11th equal highest since 1950), reflecting the sunny days, but the mean minimum was just below average. There was a relatively large range, with an absolute maximum of 12.8°C and an absolute minimum of -8.1°C, the lowest December temperature since 1995.

Rainfall was just above average, but lower than in December 2002, so the 12-month total fell, unlike the 3- and 6-month totals which recovered a little from their very low levels in November. This was only the 3rd month in 2003 to have above-average rainfall, and the largest positive deviation – a massive 9.8 mm!

It was a sunny month, remarkably so given the high rainfall, the 3rd sunniest December since 1882. There were only 9 days with no sunshine recorded, a relatively low number, the 10th equal lowest figure since 1950.

For the year as a whole, 2003 was:

The warmest year in Durham since records began in 1850, with a rounded up figure of 9.9°C. The 2-decimal figure of 9.88°C beats 2002 (9.80°C) and 1949 (9.83°C). Remarkably, the monthly running mean never edged above 10°C, but stayed pretty close all through the year!

The driest calendar year in Durham since records began (this time the complete record runs from 1852), 2003’s 408.8mm just falling below the 1989 total of 415.3mm. As noted above, only three months recorded totals (just) above average. The total is a huge 240.2mm below the long-term average for Durham – no wonder there are real worries about severe water shortages in 2004.

This is not, however, the driest 12-month period on record at Durham, but only the 12th driest in a series of 1813 12-month periods since December 1852. Years when there were even lower 12-month totals include 1905, 1949, 1959, 1973 and 1989; the driest 12-month period on record at Durham was from August 1904 to July 1905 inclusive when only 362.5mm rainfall was recorded.

The 12th sunniest year in Durham since 1882, but still more than 150 hours less than the record holder, 1989.

Professor Tim Burt
Department of Geography
Durham University