December 2013

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

Mean daily maximum: 8.9
Difference from average: +2.3

Mean daily minimum: 3.1
Difference from average: +2.0

Mean air temperature: 6.0
Difference from average:

Absolute maximum: 12.4 (12th)

Absolute minimum: -1.1 (26th)

Mean grass minimum: 0.1

Absolute grass minimum: -5.1 (26th)

Number of ground frosts: 12

Number of air frosts: 3

Mean soil temperature at 30cm depth: 6.2

Mean soil temperature at 100cm depth: 8.2

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

Total for the month: 65.4
Difference from average: +7.9

Percentage of the average: 114%

Wettest day: 10.6 (23rd)

Number of rain days (>0.25mm): 18

Number of wet days (=> 1mm): 14

3-month total rainfall to 31st December: 219.6
Difference from average: +47.6

6-month rainfall total to 31st December: 428.0
Difference from average: +81.8

12-month rainfall total to 31st December: 764.6
Difference from average: +115.6

Humidity

Relative Humidity: 83%

Sunshine
(all averages 1961 – 1990)

Total for the month: 68.2 hours
Difference from average: +22.6

Percentage of the average: 150%

Mean daily sunshine: 2.2 hours
Difference from average: +0.7

Sunniest day: 6.4 hours (26th)

Number of days with no recorded sunshine: 3

Cumulative total sunshine since 1st January: 1249.1 hours
Difference from average: -80.1

ISSN1350-483

Comments on December 2013
December was warmer than November. It was the warmest December since 1988 and the 11th highest on record since 1850. The mean maximum was the 6th equal highest (since 1900) and the mean minimum was the 9th equal highest. There was the lowest number of ground frosts since 2002.

Rainfall was slightly above average, helping to maintain longer-period totals above average. In terms of the 12-month running total, i.e. the calendar year, it was the 23rd wettest year on record at Durham since 1850. In terms of all possible 12-month totals (n=1957), 2013 was the 330th highest total. Despite average rainfall, sunshine was well above average, although the least sunny December since 2007.

Professor Tim Burt
Department of Geography
Durham University