February 2010

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

Mean daily maximum: 4.8
Difference from average: -1.2

Mean daily minimum: -0.9
Difference from average: -1.4

Mean air temperature: 2.0
Difference from average: -1.2

Absolute maximum: 7.8 (14th)

Absolute minimum: -4.7 (21st)

Mean grass minimum: -4.3

Absolute grass minimum: -10.0 (21st)

Number of ground frosts: 26

Number of air frosts: 18

Mean soil temperature at 30cm depth: 2.9

Mean soil temperature at 100cm depth: 4.9

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

Total for the month: 67.4
Difference from average: +25.8

Percentage of the average: 162%

Wettest day: 22.6 (26th)

Number of rain days (>0.25mm): 18

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

3-month total rainfall to 28th February: 210.8
Difference from average: +52.8

6-month rainfall total to 28th February: 418
Difference from average: +89.8

12-month rainfall total to 28th February: 801.3
Difference from average: +152.3

Humidity
(Averages for 09:00 hours GMT)

Relative Humidity: %

Sunshine
(all averages 1961 – 1990)

Total for the month: 56 hours
Difference from average: -9.4

Percentage of the average: 86%

Mean daily sunshine: 2 hours
Difference from average: -0.3

Sunniest day: 5.8 hours (17th)

Number of days with no recorded sunshine: 2

Cumulative total sunshine since 1st January: 119.8 hours
Difference from average: +0.6

Wind

The anemometer remains problematic, no summary results can be provided.

ISSN1350-483

Comments on February 2010
This was the coldest February since 1994 and the 35th coldest on record at Durham since 1850. Both the mean maximum and the mean minimum were also the lowest for February since 1994. The absolute maximum (7.8°C) was the lowest since 1986, when the maximum February temperature was only 3.5°C! There was a lower absolute minimum for February in 2008.

For the winter as a whole, this was as cold as the 1981-2 winter (1.9°C) with the previous coldest being 1978-79 (0.9°C); the coldest winter on record at Durham was 1962-63 (-0.1°C). It was the 17th equal coldest winter at Durham since 1850. It is interesting to note that the mean winter temperature 1941-1970 was 3.1°C whereas for 1981-2010, it is 4.0°C; on this basis, this last winter was still a little less extreme than that of 1978-79 being 2.1°C below the current average, compared to 2.2°C. Statistically, we might expect a winter as cold as this roughly every 30 years on average, so it has indeed been quite unusual!

Rainfall was above average for the 4th month in a row. As a result, it was the 27th wettest winter on record, but only the wettest since 2007.

Professor Tim Burt
Department of Geography
Durham University