January 2013

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

Mean daily maximum: 5.5
Difference from average: -0.3

Mean daily minimum: 0.8
Difference from average: +0.6

Mean air temperature: 3.2
Difference from average: +0.2

Absolute maximum: 12.1 (3rd)

Absolute minimum: -7.6 (nights of 16th & 17th)

Mean grass minimum: 0.2

Absolute grass minimum: -3.1 (10th)

Number of ground frosts: 20

Number of air frosts: 14

Mean soil temperature at 30cm depth: 4.7

Mean soil temperature at 100cm depth: 6.8

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

Total for the month: 82.0
Difference from average: +22.6

Percentage of the average: 138%

Wettest day: 18.2 (26th)

Number of rain days (>0.25mm): 21

Number of wet days (=> 1mm): 18

3-month total rainfall to 31st January: 306.2
Difference from average: +127.7

6-month rainfall total to 31st January: 615.8
Difference from average: +262.1

12-month rainfall total to 31st January: 1079.2
Difference from average: +430.2

Humidity
(Averages for 09:00 hours GMT)

Relative Humidity: 89%

Sunshine
(all averages 1961 – 1990)

Total for the month: 56 hours
Difference from average: +2.2

Percentage of the average: 104%

Mean daily sunshine: 1.8 hours
Difference from average: +0.1

Sunniest day: 6.5 hours (9th)

Number of days with no recorded sunshine: 3

ISSN1350-483

Comments on January 2013
January seemed a cold month, but the many snowy days were deceptive and it was in fact a little above average overall; nights were warmer but days colder than the average. The grass minimum temperatures are higher than expected because of the snow cover, meaning that unusually minimum air temperature was often lower than the grass minimum.

Rainfall in January was above average for the 10th month in a row. Not surprisingly, the 12-month running total was the highest on record, beating the previous month’s total. Much of the precipitation fell as snow but we no longer keep a record of days with snow lying. Sunshine was a little above average.

Professor Tim Burt
Department of Geography
Durham University