March 2018

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

Mean daily maximum: 6.9
Difference from average: -1.6

Mean daily minimum: 1.0
Difference from average: -0.6

Mean air temperature: 3.9
Difference from average: -1.1

Absolute maximum: 11.8 (20th)

Absolute minimum: -4.4 (1st)

Mean grass minimum: -0.6

Absolute grass minimum: -5.2 (20th)

Mean concrete minimum: 0.6

Absolute concrete minimum: -3.4 (21st)

Number of ground frosts: 20

Number of air frosts: 10

Mean soil temperature at 30cm depth: 4.8

Mean soil temperature at 100cm depth: 5.6

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

Total for the month: 86.4
Difference from average: +35.2

Percentage of the average: 169%

Wettest day: 12.0 (6th)

Number of rain days (>0.25mm): 18

Number of wet days (=> 1mm): 14

3-month total rainfall to 31st March: 188.8
Difference from average: +16.8

6-month rainfall total to 31st March: 329.4
Difference from average: -16.8

12-month rainfall total to 31st March: 690.2
Difference from average: +41.2

Humidity
(averages for 09:00 hours GMT)

Relative Humidity: 82%

Sunshine
(all averages 1961 – 1990)

Total for the month: 71.1 hours
Difference from average: -34.4

Percentage of the average: 67%

Mean daily sunshine: 2.3 hours
Difference from average: -1.1

Sunniest day: 8.7 hours (25th)

Number of days with no recorded sunshine: 7

Cumulative total sunshine since 1st January: 1984 hours
Difference from average: -26.3

ISSN1350-483

Comments on March 2018
March seemed a cold month, and indeed it was well below the average mean air temperature, but it ranked only equal 49th coldest since 1850, just in the bottom third; it was the coldest March since 2013. There were plenty of reasonably mild days towards the end of the month, including six days out of eight with maxima above 10°C (20th – 27th inclusive) but there were also some very cold days with snowfall, notably at the start of the month and in the middle but also on the last day too. Snow and ice seem to have interfered with the equipment on occasion, at the start of the month in particular. There were the lowest absolute minimum and absolute grass minimum temperatures for March since 2011. Precipitation was well above average. It was the 12th wettest March on record and the highest March total since 1999. It was a very dull month, duller than February indeed (despite three more days), although totals may have been reduced by snow and ice covering the solarimeter. It was the dullest March since 2013 and the 17th dullest since 1881. The unusually high tally of days with no sun may be too large, for reasons already explained.

Emeritus Professor Tim Burt
Department of Geography
Durham University