Wimbledon begins today and so will begin the traditional game of dodging the rain, with a forecast of showers over much of the UK.

Ever since the championship moved to its present ground in 1922, it has been cursed by rain. Sixteen times play has been extended into a third week to clear a backlog of matches rained off, and rain has forced play three times on the rest Sunday between the first and second weeks, most recently in 2004.

Ten years ago June was the wettest of the century and was so chilly that on June 27 the mid-afternoon temperature in London sank to only 11C (52F). To add to the misery, two days were lost to rain in the first week, and the middle Sunday was used for play for only the second time. But the tournament finished on time.

So why is Wimbledon so often rained off? In fact June is not the warm, sunny and dry month that is often assumed. True, it has the longest days of the year and the land is heating up under the sun, but the seas lapping our shores are lagging way behind and are still quite chilly.

For this reason, London’s average maximum for June is 20C (69F), compared with July’s maximum of 22C (71F). But rain can roll off the Atlantic, or bubble up into clouds from warm air on land.