By Philip Eden

After a very disturbed first week May’s weather was dominated by high pressure systems – for the first time in three years. As a consequence it was, averaged nationally, the warmest, driest, and sunniest May since 2001. Thanks to the unsettled start, however, no records were broken.

Average afternoon maximum temperatures ranged from 18.7C at Kew Gardens in southwest London to 10.6C at Fair Isle, between Orkney and Shetland. Average overnight minima varied between 10.7C in central London and 4.2C at Kindrogan in Perthshire. Throughout the UK monthly temperatures were between 1 to 2 degC above the long-term mean although a few places in eastern Scotland were more than 2 degC above. In the last 100 years, 20 Mays were warmer, two had the same mean temperature, and 78 were cooler.

There were few individual temperatures of note. The highest maximum of 25.3C was recorded in the London area on the 17th and 19th, but higher readings have occurred in every May since 1994. By contrast, the mercury sank to minus 3.7C at Kinbrace in Sutherland early on the morning of the 27th and there were several widespread ground frosts during the fourth week even in southern districts. Even so, May 2003 had delivered marginally lower temperatures.

Rainfall in England and Wales averaged 51mm which is 17 per cent below the mean for the standard reference period 1971-2000. In Scotland’s main population centres the total was 35mm (34 per cent below), and in Northern Ireland 36mm (33 per cent below). Most of that rain fell during the first week, and several places in Wales, the West Country and the Channel Islands were completely dry between the 6th and 27th inclusive. In the last 100 years, 34 Mays were drier and 66 were wetter. At a more local level, monthly totals ranged from just 15mm at Leeming in North Yorkshire to 149mm at Loch Fyne in Argyll.

Sunshine totals ranged from 125 hours at Lerwick in Shetland to 310 hours at Falmouth in Cornwall. Averaged over England and Wales, the sun shone for 217 hours last month, the most since 2001 and just 8 per cent above the long-term mean; May was sunnier in 40 of the last 100 years. With totals close to or in excess of 300 hours (approaching 10 hours per day, on average) Cornwall and south Devon enjoyed their sunniest May since 1989.

(c) Philip Eden