March 2017

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

Mean daily maximum: 11.2
Difference from average: +2.8

Mean daily minimum: 4.2
Difference from average: +2.6

Mean air temperature: 7.7
Difference from average: +2.7

Absolute maximum: 16.5 (25th)

Absolute minimum: -0.5 (26th)

Mean grass minimum: 2.3

Absolute grass minimum: -3.9 (1st)

Mean concrete minimum: 3.0

Absolute concrete minimum: -2.7 (1st)

Number of ground frosts: 7

Number of air frosts: 3

Mean soil temperature at 30cm depth: 7.6

Mean soil temperature at 100cm depth: 7.5

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

Total for the month: 42.4
Difference from average: -8.8

Percentage of the average: 83%

Wettest day: 10.6 (22nd)

Number of rain days (>0.25mm): 11

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

3-month total rainfall to 31st March: 147.6
Difference from average: -24.4

6-month rainfall total to 31st March: 322.4
Difference from average: -23.8

12-month rainfall total to 31st March: 643.9
Difference from average: -5.1

Humidity
(averages for 09:00 hours GMT)

Relative Humidity: 80%

Sunshine
(all averages 1961 – 1990)

Total for the month: 125.3 hours
Difference from average: +19.8

Percentage of the average: 119%

Mean daily sunshine: 4.0 hours
Difference from average: +0.6

Sunniest day: 11.0 hours (1st)

Number of days with no recorded sunshine: 3

Cumulative total sunshine since 1st January: 255.7 hours
Difference from average: +31.0

ISSN1350-483

Comments on March 2017
March was exceptionally mild. It was the 7th equal warmest on record since 1850 and the warmest since 2012. The mean maximum was the equal 11th warmest since 1900, although still 2.5°C cooler than the remarkable March 2012. The mean minimum was the 3rd highest since 1900, only exceeded in 1957 and 1938. Minima of 11.9°C and 10.5°C on the 30th and 31st respectively certainly helped to achieve the very high average minimum temperature. Twelve days had maximum temperatures lower than 10.5°C and 18 days were cooler than 11.9°C! There were only 7 ground frosts, the lowest March total since 1999. March 2017 is one of 10 to have had as few as 3 air frosts; only three years have had only 2 air frosts in March: 1938, 1991 and 1999. The 25th was the warmest March day in Durham since a remarkable run of 6 days at the end of 2012 were 18.7°C or warmer including the record-breaker 21.8°C (28/3/12). Rainfall was just below average and sunshine just above.

Professor Tim Burt
Department of Geography
Durham University