July 2012
July 2012
Temperatures
(all temperatures in degrees Celsius; all averages 1961 – 1990)
Mean daily maximum: 18.1
Difference from average: -1.2
Mean daily minimum: 10.6
Difference from average: +0.2
Mean air temperature: 14.4
Difference from average: -0.5
Absolute maximum: 22.8 (24th)
Absolute minimum: 5.8 (31st)
Mean grass minimum: 9.4
Absolute grass minimum: 2.5 (31st)
Number of ground frosts: 0
Number of air frosts: 0
Mean soil temperature at 30cm depth: 16.0
Mean soil temperature at 100cm depth: 14.1
Rainfall
(all totals in millimetres; all averages 1961 – 1990)
Total for the month: 97.6
Difference from average: +46.0
Percentage of the average: 189%
Wettest day: 24.8 (6th)
Number of rain days (>0.25mm): 16
Number of wet days (=> 1mm): 14
3-month total rainfall to 31st July: 309.0
Difference from average: +129.0
6-month rainfall total to 31st July: 463.4
Difference from average: +117.2
12-month rainfall total to 31st July: 779.8
Difference from average: +130.8
Humidity
(Averages for 09:00 hours GMT)
Relative Humidity: 84.1%
Sunshine
(all averages 1961 – 1990)
Total for the month: 89.3 hours
Difference from average: -65.6
Percentage of the average: 57.7%
Mean daily sunshine: 2.9 hours
Difference from average: -2.1
Sunniest day: 8.8 hours (21st)
Number of days with no recorded sunshine: 2
Cumulative total sunshine since 1st January: 749.7 hours
Difference from average: -95.2
ISSN1350-483
Comments on July 2012
July 2012 had exactly the same mean air temperature as July 2011, another disappointing below-average month, the second in a row. Days were cooler but nights warmer than a year ago. There were only 9 days when the air temperature went above 20°C.
For the 4th month in a row, rainfall was well above average. Indeed, these four months have been the third wettest of any consecutive 4 months since records began (435.4mm), beaten only by November 1978 to February 1979 (453.7mm) and in 1867 (May – August: 503mm). In just 4 months, we have gone from a major deficit to a large excess!
As with June, July was another very poor month for sunshine, well below average; this was the 5th lowest total for any July since 1882 and the worst since 1968.
Professor Tim Burt
Department of Geography
Durham University