April 2014

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

Mean daily maximum: 12.8
Difference from average: +1.8

Mean daily minimum: 5.6
Difference from average: +2.5

Mean air temperature: 9.2
Difference from average: +2.2

Absolute maximum: 18.4 (29th)

Absolute minimum: -1.5 (19th)

Mean grass minimum: 3.8

Absolute grass minimum: -4.3 (19th)

Number of ground frosts: 5

Number of air frosts: 2

Mean soil temperature at 30cm depth: 9.9

Mean soil temperature at 100cm depth: 8.7

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

Total for the month: 49.4
Difference from average: +2.1

Percentage of the average: 104%

Wettest day: 11.4 (26th)

Number of rain days (>0.25mm): 12

Number of wet days (=> 1mm): 9

3-month total rainfall to 30th April: 117.0
Difference from average: -55.0

6-month rainfall total to 30th April: 327.6
Difference from average: -18.6

12-month rainfall total to 30th April: 775.4
Difference from average: +126.4

Humidity
(averages for 09:00 hours GMT)

Relative Humidity: 83%

Sunshine
(all averages 1961 – 1990)

Total for the month: 114.8 hours
Difference from average: -18.4

Percentage of the average: 86%

Mean daily sunshine: 3.8 hours
Difference from average: -0.6

Sunniest day: 11.8 hours (16th)

Number of days with no recorded sunshine: 3

Cumulative total sunshine since 1st January: 392.9 hours
Difference from average: +35.1

ISSN1350-483

Comments on April 2014
April was another warm month, well above average, the 7th equal warmest April on record at Durham since 1850 – but only the warmest April since record-breaking 2011 (mean = 11.2°C). Rainfall was just about average; the 6-month total has now fallen below average but the 12-month total remains well above. April was less sunny than March but this is not unusual having happened in 39 out of 131 years of record.

Professor Tim Burt
Department of Geography
Durham University