May 2002

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

Mean daily maximum: 14.9
Difference from average: +0.6

Mean daily minimum: 7.6
Difference from average: +2.3

Mean air temperature: 11.3
Difference from average: +1.4

Absolute maximum: 22.6 (17th)

Absolute minimum: 1.3 (5th)

Mean grass minimum: 6.0

Absolute grass minimum: -1.8 (5th)

Number of ground frosts: 5

Number of air frosts: 0

Mean soil temperature at 30cm depth: 12.5

Mean soil temperature at 100cm depth: 11.3

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

Total for the month: 57.6
Difference from average: +5.4

Percentage of the average: 110%

Wettest day: 7.0 (4th)

Number of rain days (>0.1mm): 22

3-month total rainfall to 31st May: 111.8
Difference from average: -39.4

6-month rainfall total to 31st May: 268.8
Difference from average: -40.3

12-month rainfall total to 31st May: 536
Difference from average: -113

Humidity
(Averages for 09:00 hours GMT)

Relative Humidity: 75%

Sunshine
(all averages 1961 – 1990)

Total for the month: 141.4 hours
Difference from average: -27.1

Percentage of the average: 84%

Mean daily sunshine: 4.6 hours
Difference from average: -0.8

Sunniest day: 12.7 hours (5th)

Number of days with no recorded sunshine: 3

Cumulative total sunshine since 1st January: 582.5 hours
Difference from average: +56.1

Wind

The mean wind speed: 14.4km/h [7.8 kt]
Difference from average: +2.0km/hr

The highest gust: 81.5km/h [44 kt] from 211° at 17:32 GMT on 24th

ISSN1350-483

Comments on May 2002
May was another warm month, 16th warmest on record since 1850, although 0.3°C cooler than May 2001! Not surprisingly, given that we had the 12th warmest March and the 8th warmest April, Spring 2002 turned out to be exceptionally warm (average 9.0°C), 2nd warmest on record, and only exceeded by 1945 (9.2°C). There were few ground frosts and no air frosts. Rainfall was just a little above average and, given the large number of rain days, sunshine was a little below average. Rainfall in spring as a whole was a little below average, but not exceptionally so.

Professor Tim Burt
Department of Geography
Durham University