April 2013

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

Mean daily maximum: 10.8
Difference from average: -0.2

Mean daily minimum: 3.1
Difference from average: 0.0

Mean air temperature: 7.0
Difference from average: -0.1

Absolute maximum: 16.9 (24th)

Absolute minimum: -2.2 (3rd)

Mean grass minimum: 0.5

Absolute grass minimum: -6.6 (3rd)

Number of ground frosts: 16

Number of air frosts: 4

Mean soil temperature at 30cm depth: 6.9

Mean soil temperature at 100cm depth: 6.3

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

Total for the month: 22.8
Difference from average: -24.5

Percentage of the average: 48%

Wettest day: 7.0 (25th)

Number of rain days (>0.25mm): 14

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

3-month total rainfall to 30th April: 115.4
Difference from average: -24.8

6-month rainfall total to 30th April: 421.6
Difference from average: 102.9

12-month rainfall total to 30th April: 1032.2
Difference from average: 383.3

Humidity
(Averages for 09:00 hours GMT)

Relative Humidity: 72%

Sunshine
(all averages 1961 – 1990)

Total for the month: 134.6 hours
Difference from average: +1.4

Percentage of the average: 101%

Mean daily sunshine: 4.5 hours
Difference from average: +0.1

Sunniest day: 11.1 hours

Number of days with no recorded sunshine: 0

Cumulative total sunshine since 1st January: 329.5 hours
Difference from average: -28.3

ISSN1350-483

Comments on April 2013
April is the cruelest month, as T.S. Eliot wrote! April felt very disappointing but in fact temperatures were only just below average; it was nevertheless colder than last April. Until the 13th, only one day exceeded 10°C; thereafter they all did! The absolute maximum (16.9°C) is quite typical for April but nowhere near the 23.3°C of April 2007!

Spring seemed very slow in coming!

April was a dry month, less than half the usual amount of rainfall. It is only the 2nd month in the last 12 to have below-average rainfall (February 2013 was the other). For the 5th month in a row, the 12-month total was above 1000mm, but much lower than at the end of March; this April was dry whereas last April was extremely wet. Despite the low rainfall total, sunshine was only just about average.

Professor Tim Burt
Department of Geography
Durham University