September 2014

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

Mean daily maximum: 18.1
Difference from average: +1.4

Mean daily minimum: 9.9
Difference from average: +1.2

Mean air temperature: 14.0
Difference from average: +1.3

Absolute maximum: 22.3 (5th)

Absolute minimum: 6.0 (21st)

Mean grass minimum: 8.8

Absolute grass minimum: 4.3 (21st)

Number of ground frosts: 0

Number of air frosts: 0

Mean soil temperature at 30cm depth: 16.2

Mean soil temperature at 100cm depth: 15.4

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

Total for the month: 21.0
Difference from average: -34.6

Percentage of the average: 37.8%

Wettest day: 7.0 (6th)

Number of rain days (>0.25mm): 9

Number of wet days (=> 1mm): 5

3-month total rainfall to 30th September: 144.4
Difference from average: -27.6

6-month rainfall total to 30th September: 337.4
Difference from average: -8.8

12-month rainfall total to 30th September: 715.8
Difference from average: +66.8

Humidity
(averages for 09:00 hours GMT)

Relative Humidity: 83%

Sunshine
(all averages 1961 – 1990)

Total for the month: 116.7 hours
Difference from average: -7.3

Percentage of the average: 94%

Mean daily sunshine: 3.9 hours
Difference from average: -0.2

Sunniest day: 12.0 hours (12th)

Number of days with no recorded sunshine: 2

Cumulative total sunshine since 1st January: 1054.8 hours
Difference from average: -69.6

ISSN1350-483

Comments on September 2014
September was just about as warm as August. It was the 11th equal warmest September at Durham since 1850 although only the warmest since 2011. It was also a very dry month, the 23rd driest September since 1850 and the driest since 2004.

We should note some problems with data access at the end of the month when the link to the Met Office failed irrevocably. Thanks to Ken Cook for providing comparative data from which some estimates could be made for the 29th and 30th.

Professor Tim Burt
Department of Geography
Durham University