A warning has been issued to millions of Britons with temperatures set to be unseasonably hot today, reaching highs of 10C above the average for April in some areas today. London is expected to enjoy a high of 22C while large parts of the south will also jump into the twenties as the UK continues to bask in sunshine.

The Met Office believes that a high of 23C could be seen in East Wales, with the country set to enjoy a warm start to the weekend. Temperatures for this time of year average at around 13C with London Fire Brigade (LFB) issuing a stark warning about the risk of fire for those set to make the most of the heightened temperatures. LFB assistant commissioner Thomas Goodall said: "The risk of wildfires in London currently is heightened and this risk increases with every day that passes without rainfall. Over the Easter holidays, parents should ensure that their children understand the fire risks to help protect our open spaces."

Last weekend, which also saw sunny conditions across the UK, the LFB received a 48% increase in calls compared to the same weekend the previous year.

Mr Goodall urged Londoners to "take steps to ensure they are not inadvertently starting a fire."

He added: "They can do this by not using barbecues in open spaces or on balconies, including disposable ones, to throw rubbish away, and to dispose of cigarettes carefully."

The drier conditions over the last week saw wildfires reported in Scotland, Dorset and South Wales, cemphasising the need for the public to heed warnings. Firefighters fought for several hours to eventually bring the wildfires under control.

A Met Office forecast for Friday says: "Any low cloud, most and fog will clear this morning to leave a fine and warm day for many, with plenty of sunshine.

“Cloudier skies across northern Scotland. Breezy here, with outbreaks of rain developing across the Northern Isles."

Met Office meteorologist Dan Stroud said: "We've got high pressure at the moment, which effectively acts like a force field.

"It actually keeps fronts and clouds largely at bay and keeps conditions settled and dry underneath the area of high pressure."

However the agency has warned that the sunny conditions could soon come to a close, with a period of wet weather to follow in days

Met Office Deputy Chief Meteorologist Mark Sidaway explained: "The high pressure that has been responsible for our recent high temperatures gradually shifts away over the weekend, as more of an unsettled regime begins to take charge and introduces more frequent rain and cloud, as well as a drop in temperatures.

"Those in the far northwest will see the first of the rain late on Friday and into Saturday, and while Saturday will start dry for much of the UK, we are likely to see areas of showers moving in from the south later in the day, although this aspect is still quite uncertain. However, by Sunday fresher conditions with showers are expected to move in from the west."