April 2006

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

Mean daily maximum: 12.1
Difference from average: +1.1

Mean daily minimum: 3.9
Difference from average: +0.8

Mean air temperature: 8.0
Difference from average: +1.0

Absolute maximum: 16.6 (26th)

Absolute minimum: -1.3 (10th)

Mean grass minimum: 1.8

Absolute grass minimum: -4.1 (5th)

Number of ground frosts: 10

Number of air frosts: 3

Mean soil temperature at 30cm depth: 8.6

Mean soil temperature at 100cm depth: 7.6

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

Total for the month: 7.4
Difference from average: -40.1

Percentage of the average: 16%

Wettest day: 3.2 (9th)

Number of rain days (>0.25mm): 5

Number of wet days (=> 1mm): 2

3-month total rainfall to 30th April: 91.4
Difference from average: -49.2

6-month rainfall total to 30th April: 223
Difference from average: -95.9

12-month rainfall total to 30th April: 528.5
Difference from average: -120.5

Humidity
(Averages for 09:00 hours GMT)

Relative Humidity: 68%

Sunshine
(all averages 1961 – 1990)

Total for the month: 160.9 hours
Difference from average: +27.7

Percentage of the average: 121%

Mean daily sunshine: 4.8 hours
Difference from average: 0.4

Sunniest day: 11.7 hours (23rd)

Number of days with no recorded sunshine: 2

Cumulative total sunshine since 1st January: 240.3 hours
Difference from average: -117.5

Wind

The mean wind speed: 17.4km/h [9.4kt]
Difference from average: +4.1km/hr

The highest gust: 87km/h [47kt] from 241° at 09:15 GMT on 13th

ISSN1350-483

Comments on April 2006
After two wet Aprils in 2004 and 2005 (both totals in the top 20% for April), this was the 5th driest April on record, with only 7.4mm of rainfall recorded. Such a low total raises inevitable suspicions about the gauge being blocked at some stage, but it was regularly checked by the Geography Department technicians and so we must assume the low total is correct. Hopefully, the nearby Barkers Haugh gauge will provide confirmation in due course. Maps on the Met Office website show that the total should be below 25mm, so this confirms a dry month in the north east.

Temperatures returned to their regular above-average state after a cold March. Given low rainfall, it was not surprising that the monthly total of bright sunshine hours was above average for the first time this year. Wind speed was well above average and there was a notable gust of 87 km/h on the 13th.

Professor Tim Burt
Department of Geography
Durham University