April 2002

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

Mean daily maximum: 13.4
Difference from average: +2.4

Mean daily minimum: 4.1
Difference from average: +1.0

Mean air temperature: 8.8
Difference from average: +1.7

Absolute maximum: 19.8 (24th)

Absolute minimum: -2.0 (11th)

Mean grass minimum: 1.9

Absolute grass minimum: -5.7 (7th)

Number of ground frosts: 11

Number of air frosts: 4

Mean soil temperature at 30cm depth: 10.0

Mean soil temperature at 100cm depth: 9.0

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

Total for the month: 14.8
Difference from average: -33.0

Percentage of the average: 31%

Wettest day: 3.8 (30th)

Number of rain days (>0.1mm): 13

3-month total rainfall to 30th April: 141.8
Difference from average: -9.8

6-month rainfall total to 30th April: 247
Difference from average: -49.7

12-month rainfall total to: 486.2
Difference from average: -162.2

Humidity
(Averages for 09:00 hours GMT)

Relative Humidity: 75.3%

Sunshine
(all averages 1961 – 1990)

Total for the month:  171.9 hours
Difference from average: +38.7

Percentage of the average: 129%

Mean daily sunshine: 5.7 hours
Difference from average: +1.3

Sunniest day: 12.0 hours (24th)

Number of days with no recorded sunshine: 0

Cumulative total sunshine since 1st January: 441.1 hours
Difference from average: +83.2

Wind

The mean wind speed: 12.0km/h [6.5 kt]
Difference from average: -2.3km/hr

The highest gust: 75.9km/h [41 kt] from 262° at 13:54 GMT on 29th

ISSN1350-483

Comments on April 2002
For the fourth month in a row, mean air temperature was well above average. In fact, it was the warmest April in Durham since 1987, the 8th warmest on record. Maximum temperatures in particular were well above average, minimum temperatures less so. It was a dry month, well below average: the driest April since 1997, and 17th driest since 1852. Overall, the 12-month total to April 2002 is now well below the 12-month average, in stark contrast to conditions 12 months previous when the 12-month total was well above average. April was a sunny month, and for the first time since 1982, some sunshine was recorded every day.

Professor Tim Burt
Department of Geography
Durham University