May 2008

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

Mean daily maximum: 15.6
Difference from average: +1.3

Mean daily minimum: 7.1
Difference from average: +1.6

Mean air temperature: 11.4
Difference from average: +1.5

Absolute maximum: 23.7 (10th)

Absolute minimum: -0.9 (20th)

Mean grass minimum: 5.1

Absolute grass minimum: -3.6 (20th)

Number of ground frosts: 5

Number of air frosts:

Mean soil temperature at 30cm depth: 13.4

Mean soil temperature at 100cm depth: 11.5

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

Total for the month: 21.6
Difference from average: -30.2

Percentage of the average: 42%

Wettest day: 9.6 (29th)

Number of rain days (>0.25mm): 5

Number of wet days (=> 1mm): 4

3-month total rainfall to 31st May: 144
Difference from average: -6.4

6-month rainfall total to 31st May: 310.6
Difference from average: +2.1

12-month rainfall total to 31st May:
Difference from average: +27.4

Humidity
(Averages for 09:00 hours GMT)

Relative Humidity: 76.5%

Sunshine
(all averages 1961 – 1990)

Total for the month: 154.7 hours
Difference from average: -13.8

Percentage of the average: 92%

Mean daily sunshine: 5 hours
Difference from average: -0.4

Sunniest day: 12.3 hours (5th)

Number of days with no recorded sunshine: 5

Cumulative total sunshine since 1st January: 541.6 hours
Difference from average: +15.3

Wind

The mean wind speed: 9.3km/h [5kt]
Difference from average: -3.0km/hr

The highest gust: 48.2km/h [26kt] from 5° at 13:51 GMT on 25th

[Note: the results given here are not based on “thrown back” values; adjusted values will be issued in due course]

ISSN1350-483

Comments on May 2008
Despite seeming somewhat disappointing, perhaps because there was only an average amount of bright sunshine, it was nevertheless the 17th equal warmest May at Durham since 1850, and the warmest since 2003. It was also a dry month: the driest May since 2005 and 22nd equal driest on record. All long-term totals are now close to average again. There were the most days without bright sunshine since 1993. It was also a relatively calm month, with a maximum gust of only 48 km/h.

Professor Tim Burt
Department of Geography
Durham University