November 2012

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

Mean daily maximum: 9.2
Difference from average: +0.5

Mean daily minimum: 2.8
Difference from average: +0.1

Mean air temperature: 6.0
Difference from average: +0.3

Absolute maximum: -7.3 (13th)

Absolute minimum: -3.1 (30th)

Mean grass minimum: 0.0

Absolute grass minimum: -7.3 (30th)

Number of ground frosts: 16

Number of air frosts: 5

Mean soil temperature at 30cm depth: 8.1

Mean soil temperature at 100cm depth: 10.0

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

Total for the month: 124.4
Difference from average: +62.4

Percentage of the average: 201%

Wettest day: 49.4 (26th)

Number of rain days (>0.25mm): 16

Number of wet days (=> 1mm): 11

3-month total rainfall to 30th November: 330.2
Difference from average: +160.1

6-month rainfall total to 30th November: 670.2
Difference from average: +329.7

12-month rainfall total to 30th November: 982.4
Difference from average: +333.4

Humidity
(Averages for 09:00 hours GMT)

Relative Humidity: 89%

Sunshine
(all averages 1961 – 1990)

Total for the month: 75.8 hours
Difference from average: +9.7

Percentage of the average: 115%

Mean daily sunshine: 2.5 hours
Difference from average: +0.3

Sunniest day: 5.5 hours (7th)

Number of days with no recorded sunshine: 0

Cumulative total sunshine since 1st January: 1174 hours
Difference from average: -109.6

ISSN1350-483

Comments on November 2012
Just like September, November was another extraordinary month for rainfall, three days in particular. The total of 49.4mm on 26th was the 24th largest daily total since 1850; the 2-day total (25th + 26th) was the 21st highest 2-day total on record whilst the 3-day total (25th – 27th) was 13th highest 3-day total on record. It rained for 11 hours on the 25th, for 19 hours on the 27th and, remarkably, rainfall was recorded in all 24-hour periods on the 26th. The maximum hourly intensity was 4.6mm (11.00am – 12.00am, 26th), part of a total of 15.6mm during the period 9.00am – 1.00pm on the 26th.

It was the 12th wettest November since 1850. The 6-month total (June – November inclusive) is the highest total for any 6-month period since 1850; thus, the wettest summer and autumn on record. This is only the second time that a 6-month total has exceeded the mean annual rainfall total at Durham, the other occasion being the 6-month total to the end of September. The 3-month (autumn) total is the 17th highest on record, whilst the 12-month total (i.e. December 2011 to November 2012 inclusive) is the 4th highest on record, beaten only in 2001 and 1872 (twice). Hardly surprisingly, the 8-month total (since April) is the highest on record for any 8-month period at Durham, beating the previous record form 1853. Even if December is completely dry, 2012 is already set to be the wettest calendar year on record at Durham since 1850, beating the previous record set in 1872, which was itself a remarkably wet year across the British Isles.

Meanwhile, average temperature was a little above average, sunshine too.

Professor Tim Burt
Department of Geography
Durham University