The driest April on record has left much of Britain's uplands tinder dry and prone to wildfire

April was the warmest on record, according to provisional figures released by the Government’s official weather organisation.

The Met Office said April 2011 was also the 11th driest on record – with only half the average rainfall across the UK.

Temperatures across the UK were 3C to 5C warmer than normal, with an average of 10.7C, the warmest for 100 years, beating the previous high of 10.2C set in 2007.

The Met Office said: “The dry weather this April has been largely caused by ‘blocked’ weather patterns across the UK. This weather pattern has prevented the usual run of westerly winds off the Atlantic Ocean, which bring rain-bearing fronts.

“The dry April for many follows a dry March when less than half of the normal rainfall fell across the UK, also followed by a drier than average winter.”

However, the pattern was not uniform, with parts of north and west Scotland seeing about 110 per cent of normal April rainfall, while parts of south and east England have seen less than 10 per cent of normal precipitation.

The UK average rainfall total was 36.7mm – 52 per cent of the long-term average.

Widespread wildfires have affected many parts of the UK as strong winds help spread moor, heath and woodland fires in Lancashire, Cumbria, West Yorkshire, Kintail, Torridon, the Mourne Mountains of Northern Ireland, Cumbria, Strath Fillan, Berkshire, Lochaber, Aberdeenshire and the Queen’s estate at Balmoral.

The Mountain Weather Information Service says the high pressure northeast of Britain will weaken slowly, allowing Atlantic fronts to edge east into Britain from Thursday, bringing cloud outbreaks of rain, mainly in the West. By the weekend, most mountain areas are expected to become warm again, but with the fronts still over the country, outbreaks of rain and probably bands of thundery weather will move north from the Continent.