July 2005

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

Mean daily maximum: 19.8
Difference from average: +0.5

Mean daily minimum: 11.8
Difference from average: +1.4

Mean air temperature: 15.8
Difference from average: +1.0

Absolute maximum: 28.2 (13th)

Absolute minimum: 7.9 (8th)

Mean grass minimum: 11.6

Absolute grass minimum: 8.0 (8th)

Number of ground frosts: 0

Number of air frosts: 0

Mean soil temperature at 30cm depth: 9.2

Mean soil temperature at 100cm depth: 8.8

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

Total for the month: 66.4
Difference from average: +18.9

Percentage of the average: 140%

Wettest day: 39.8 (15th)

Number of rain days (>0.25mm): 10

Number of wet days (=> 1mm): 4

3-month total rainfall to 31st July: 144.4
Difference from average: +3.8

6-month rainfall total to 31st July: 201.2
Difference from average: -117.7

12-month rainfall total to 31st July: 650.6
Difference from average: +1.6

Humidity
(Averages for 09:00 hours GMT)

Relative Humidity: 75.5%

Sunshine
(all averages 1961 – 1990)

Total for the month: 144 hours
Difference from average: +10.8

Percentage of the average: 108.1%

Mean daily sunshine: 4.6 hours
Difference from average: +0.2

Sunniest day: 10.8 hours (22nd)

Number of days with no recorded sunshine: 3

Cumulative total sunshine since 1st January: 326.5 hours
Difference from average: -31.3

Wind

The mean wind speed: 16.1km/h [8.7kt]
Difference from average: +2.2km/hr

The highest gust: 77.8km/h [42kt] from 186° at 07:44 GMT on 6th

ISSN1350-483

Comments on July 2005
July was warmer than average, but not exceptionally so, lying just within the interquartile range, 117th in a series of 157. Minimum temperatures were well above average, more so than maximum temperatures, reflecting the relatively cloudy and wet month. Total sunshine was just below average, whilst total rainfall was above average. The 5th, 6th and especially the 28th were wet days. In between there were some warm days, with daily maxima exceeding 20° from the 9th to the 19th. We must go back to 1968 to find a July with more days without any bright sunshine at all. In all, therefore, a somewhat mixed month but with some warm, sunny summer weather in the middle of the month.

Professor Tim Burt
Department of Geography
Durham University