Sun-starved Brits can rejoice from Monday as a blistering heatwave is expected to arrive, before pushing temperatures close to 30C.
But while most will see bright skies some areas will be plunged into a patch of dense fog this morning after forecasters issued a severe weather warning.
Monday will see the beginning of a spell of hot weather that is forecast to last until at least Wednesday.
Meteorologists predict the mercury could top 29C, after warmer skies across much of the country on Sunday.
And the temperature will be so hot it is expected to beat the average for September, which is 18C in the UK.
Annie Shuttleworth, a Met Office forecaster said: "We are expecting temperatures to rise at the beginning of the new week.
"Despite a cloudy start to Monday, conditions will be clear and bright with hot temperatures for large parts of England and eastern Wales as the result of continental air moving in from the south.
"This air will start to push through the country on Tuesday and Wednesday, dragging temperatures as high as 29C (84.2F) for parts of the south-east while Scotland and Northern Ireland will also move into the mid-twenties.
"It's going to be very warm for the time of year and could even be rather uncomfortable for people trying to sleep at night, with temperatures remaining at around 18C during the evening."
Ms Shuttleworth said this meant a "decent chance" of an official heatwave for parts of central England and eastern Wales, where the temperature threshold needed over three days is 25C.
It comes after a long spell of cold and wet weather during August leading to a washout summer for many.
Meanwhile, the Met Office has issued a severe weather warning for fog for parts of the south west on Monday morning.
Experts said those in the affected area should expect longer journey times with delays to buses, trains and flights.
The warning is in place until 9am this morning and affects much of the south Wales coastline as well as the south west of England.
UK Weather Forecast
Today:
Scotland, Northern Ireland and northern England starting mostly cloudy with some rain or drizzle, becoming confined to western Scotland later. Else, dry with sunny periods, after fog clears from south-western areas. Very warm inland in central and southern areas.
Tonight:
Cloudy with light rain or drizzle in the west of Scotland and Northern Isles. Other areas dry with clear periods, allowing some mist and fog patches to form in places.
Tuesday:
Some drizzle over far north and northwest, else dry and sunny for most areas after early mist, fog and patchy low cloud clears. Becoming hot inland over England and Wales.
