May was, to borrow a phrase, a month of two halves. The first half most of us have already forgotten, and we should therefore remind ourselves that it was largely dry, sunny, and very warm – in fact it was the warmest May 1-15 since 1945. The second half we all remember; suffice to say that it was the wettest May 16-31 since 1979.
The Central England Temperature for May, which includes both daytime maxima and overnight minima, was 12.2C which is 0.9 degC above the average for the standard reference period 1971-2000, and it was the warmest May by this measure for five years. During the last 100 years there were 20 warmer Mays, four with the same mean temperature, and 76 colder.
The month’s highest temperature of 27.7C was reported at Northolt in northwest London on the 4th, but 25C was also reached in the Western Highlands on the 11th. The lowest maximum was just 4.8C on the 23rd at Boltshope Park in County Durham, while the coldest night was that of the 13th/14th when Kinbrace in Sutherland reported a minimum of –5.9C.
Rainfall, averaged over England and Wales, was 114.9mm which is 87 per cent above the mean for the standard reference period 1971-2000, making it the wettest May since 1979 when the total was 119mm; in the last 100 years 95 Mays were drier and only five were wetter. The equivalent figure for Scotland was 33 per cent above, and for Northern Ireland 67 per cent above.
It was relatively dry in Shetland, Orkney, and the Channel Isles where St Peter Port collected only 38mm of rain, the month’s lowest total to hand, and some 25 per cent below the local average. By contrast, Milford Haven logged three times its normal rainfall.
Sunshine over England and Wales totalled 179 hours which is 12 per cent below the average for 1971-2000; in the last 100 years there were 66 sunnier Mays and 34 duller. The equivalent figure for Scotland was 20 per cent above, and for Northern Ireland 10 per cent above. It was a very sunny May in the Northern and Western Isles, but a very dull one in East Anglia and southern England.
© Philip Eden