November 2011

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

Mean daily maximum: 11.4
Difference from average: +2.7

Mean daily minimum: 5.8
Difference from average: +3.1

Mean air temperature: 8.6
Difference from average: +2.9

Absolute maximum: 15.6 (3rd)

Absolute minimum: -2.5 (7th)

Mean grass minimum: -3.8

Absolute grass minimum: -5.9 (7th)

Number of ground frosts: 3

Number of air frosts: 2

Mean soil temperature at 30cm depth:

Mean soil temperature at 100cm depth:

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

Total for the month: 27.0
Difference from average: -35.0

Percentage of the average: 44%

Wettest day: 5.2 (25th)

Number of rain days (>0.25mm): 15

Number of wet days (=> 1mm): 8

3-month total rainfall to 30th November: 106.4
Difference from average: -4.8

6-month rainfall total to 30th November: 372.0
Difference from average: +31.5

12-month rainfall total to 30th November: 600.2
Difference from average: -48.8

Humidity
(Averages for 09:00 hours GMT)

Relative Humidity: 92%

Sunshine
(all averages 1961 – 1990)

Total for the month: 53.2 hours
Difference from average: -12.9

Percentage of the average: 80%

Mean daily sunshine: 1.7 hours
Difference from average: -0.5

Sunniest day: 7.5 hours (6th)

Number of days with no recorded sunshine:

Cumulative total sunshine since 1st January: 1296.0 hours
Difference from average: +12.4

Wind

The mast is still broken, we hope to replace it soon.

ISSN1350-483

Comments on November 2011
This was a remarkably warm month, the warmest November at Durham since records began in 1850, beating the previous record by 0.2°C (1994). Both mean maximum and mean minimum were well above average: the mean maximum was the 2nd highest for November, beaten only in 1994, and the mean minimum was the highest on record, beating the previous one set in 1953. There was the lowest number of ground frosts (3) since my records begin in 1961 (equal number in 1984) and only 2 air frosts. The 12-month running mean has now reached 9.53°C, the highest since March 2008.

It was also a very dry month, only 44% of the average amount: the 24th driest November since 1850 and the lowest November total since 2004 when only 14.4 mm was recorded. Whilst the number of rain days was not exceptionally low, 8th equal lowest since 1961, the daily total only exceeded 1mm on eight days and the highest daily total was only 5.2mm (25th). Although there was little rain, sunshine was below average in November.

2011 was the 2nd warmest autumn at Durham since 1850 (11.3°C), beaten only by the remarkable 2006 (12.0°C). It was the 18th driest autumn since 1850 (106.4mm), the lowest autumn total since 1989. Sunshine was below average for autumn (258.9 hours), despite being so dry, 44th lowest since 1882.

Professor Tim Burt
Department of Geography
Durham University