December 2016

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

Mean daily maximum: 8.4
Difference from average: +1.8

Mean daily minimum: 3.7
Difference from average: +2.6

Mean air temperature: 6.1
Difference from average: +2.2

Absolute maximum: 14.8 (7th)

Absolute minimum: -3.1 (5th)

Mean grass minimum: 1.7

Absolute grass minimum: -6.0 (5th)

Mean concrete minimum: 1.7

Absolute concrete minimum: -4.0 (5th)

Number of ground frosts: 8

Number of air frosts: 3

Mean soil temperature at 30cm depth: 6.6

Mean soil temperature at 100cm depth: 8.2

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

Total for the month: 36.6
Difference from average: -20.9

Percentage of the average: 64%

Wettest day: 10.4 (8th)

Number of rain days (>0.25mm): 12

Number of wet days (=> 1mm): 8

3-month total rainfall to 31st December: 174.8
Difference from average: +2.8

6-month rainfall total to 31st December: 324.0
Difference from average: -22.2

12-month rainfall total to 31st December: 698.9
Difference from average: +49.9

Humidity
(averages for 09:00 hours GMT)

Relative Humidity: 87%

Sunshine
(all averages 1961 – 1990)

Total for the month: 68 hours
Difference from average: +26.6

Percentage of the average: 149%

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

Sunniest day: 6.8 hours (28th)

Number of days with no recorded sunshine: 2

Cumulative total sunshine since 1st January: 1160.2 hours
Difference from average: -169.0

ISSN1350-483

Comments on December 2016
December was very mild, but even so, rather cooler than 2015’s record-breaker. The mean air temperature was the 12th warmest since 1850. The mean maximum was 12th equal highest and the mean minimum the 6th highest, both since 1900. There was a warmer day last December, but other than that, the maximum of 14.8°C on the 7th was the warmest December day since 2001. December was a dry month, with only two thirds of the normal amount of rain. Not surprisingly therefore, December was sunny month, the 15th sunniest December since 1882.

2016 was the 17th warmest year (9.4°C) at Durham since 1850, 0.1°C warmer than last year. Of the 16 warmer years, nine have been since 2000; in a stationary series, only two would be expected. Only two months fell below the 1961-1990 average temperature: April and November. Whilst the decadal running mean for annual temperature has fallen slightly from a peak in 2002 (9.7°C), it remains higher than at any stage before 1998. The annual rainfall total (698.9mm) was 49.9mm above average but this is not an exceptional total, ranking 58th highest in 168 years. It was a dull year (1160.2 hours), only 89% of the normal amount of sunshine, the 10th least sunny year since 1882.

Professor Tim Burt
Department of Geography
Durham University