January 2007

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

Mean daily maximum: 9.4
Difference from average: +3.6

Mean daily minimum: 3.1
Difference from average: +2.9

Mean air temperature: 6.3
Difference from average: +3.3

Absolute maximum: 12.9 (13th)

Absolute minimum: -1.3 (23rd)

Mean grass minimum: 0.7

Absolute grass minimum: -5.9 (30th)

Number of ground frosts: 12

Number of air frosts: 6

Mean soil temperature at 30cm depth: 5.6

Mean soil temperature at 100cm depth: 7.5

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

Total for the month: 50
Difference from average: -9

Percentage of the average: 85%

Wettest day: 13.4 (1st)

Number of rain days (>0.25mm): 13

Number of wet days (=> 1mm): 13

3-month total rainfall to 31st January: 233.6
Difference from average: +55.1

6-month rainfall total to 31st January: 382.4
Difference from average: +28.7

12-month rainfall total to 31st January: 638.7
Difference from average: -10.3

Humidity
(Averages for 09:00 hours GMT)

Relative Humidity: 79.8%

Sunshine
(all averages 1961 – 1990)

Total for the month: 94.1 hours
Difference from average: +40.3

Percentage of the average: 175%

Mean daily sunshine: 3.0 hours
Difference from average: +1.3

Sunniest day: 6.1 hours (27th)

Number of days with no recorded sunshine: 1

Wind

The mean wind speed: 22.6km/h [12.2kt]
Difference from average: +7.6km/hr

The highest gust: 100km/h [54kt] from 234° at 15:21 GMT on 10th

ISSN1350-483

Comments on January 2007
This was the 2nd warmest January on record since 1850; only 1916 has been milder. It is interesting to note the top ten warmest Januaries on record: unusually, there is a great spread of dates without any concentration of recent years.

1916 – 7.0
2007 – 6.3
1989 – 6.3
1898 – 6.3
1923 – 5.8
1983 – 5.7
1921 – 5.7
1884 – 5.7
1975 – 5.6
2005 – 5.5

Not surprisingly, given some record-breaking months in 2006, the 12-month average has risen above 10°C once again, for the first time since January 2005. Indeed, the average for the last 12 months (10.15°C) is equal highest with the 12-month period ending in February 2004, thus the warmest ‘year’ in Durham’s history. Of 1874 12-month periods since 1852, only 9 have exceeded 10°C, all since 2002.

Rainfall was just below average, but sunshine was well above: it was the sunniest January since records began in 1882, beating 1959 by 0.1 hour! There were twelve ground frosts, mainly in the latter part of the month, with a similar pattern for the six air frosts.

Very notable was the windiness of the middle part of the month. It was the third windiest January since 1953 (when my available record starts), beaten only by 1974 and 1975. There was a gust of 100 kph (62.5 mph) on the 10th.

Professor Tim Burt
Department of Geography
Durham University