January 2018

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

Mean daily maximum: 6.3
Difference from average: +0.5

Mean daily minimum: 1.9
Difference from average: +1.7

Mean air temperature: 4.1
Difference from average: +1.1

Absolute maximum: 13.6 (28th)

Absolute minimum: -5.5 (8th)

Mean grass minimum: 0.0

Absolute grass minimum: -9.3 (8th)

Mean concrete minimum: 0.7

Absolute concrete minimum: -3.6 (8th)

Number of ground frosts: 15

Number of air frosts: 7

Mean soil temperature at 30cm depth: 4.4

Mean soil temperature at 100cm depth: 6.1

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

Total for the month: 63.4
Difference from average: +4.0

Percentage of the average: 107%

Wettest day: 16.6 (4th)

Number of rain days (>0.25mm): 18

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

3-month total rainfall to 31st January: 173.4
Difference from average: +1.4

6-month rainfall total to 31st January: 341.4
Difference from average: -4.8

12-month rainfall total to 31st January: 688.6
Difference from average: +39.6

Humidity
(averages for 09:00 hours GMT)

Relative Humidity: %

Sunshine
(all averages 1961 – 1990)

Total for the month: 53.9 hours
Difference from average: +0.1

Percentage of the average: %

Mean daily sunshine: 1.7 hours
Difference from average: 0

Sunniest day: 5.7 hours (8th)

Number of days with no recorded sunshine: 3

ISSN1350-483

Comments on January 2018
January was warmer than average but not exceptionally so: the mean air temperature was only in the 3rd quartile. Nights were more above average temperature than days; the mean minimum temperature was the equal 19th warmest since 1900, so easily in the upper quartile (n=119). Both rainfall and sunshine hours were very close to the average for January.

Please note a gap in the data logger record from 10:00 on 4th to 09:00 on 6th. I am grateful to Ken Cook for infill data. The maximum daily rainfall (16.6mm) was one of the missing days in Durham so there must be some small doubt about the actual amount received at the Observatory.

Emeritus Professor Tim Burt
Department of Geography
Durham University