The washout weather is set to return in time for the weekend as torrential rain lashes the country with thunderstorms rumbling in some regions.
A weather warning for rain is in force for parts of Scotland on Friday after heavy rain already drenched the nation.
Temperatures, which had soared to nearly 30C earlier this week, are now back to far cooler levels.
Across much of the country the mercury will barely peak above 20C today, with most areas seeing average temperatures in the mid-teens.
The Met Office predicts that on Friday rain showers will happen 'almost everywhere', with the heaviest and most thundery to lash the north and east.
At the weekend showers will remain but be less widespread and there will be a possibility of thunderstorms.
In Scotland after heavy downpours and thunderstorms already soaked the nation a new weather warning is in force until 8am today.
The warning for more rain affects the north east of the country and predicts up to 40mm of rain to fall.
Forecasters said those in the affected area should prepare for flooding of homes and businesses as well as travel disruption.
There could also be power cuts and impacts across other services.
Meanwhile, Brits have been given hope of one final mini-heatwave for the year.
Long range forecasts say that a nine-day heat spell could hit the UK next week.
According to BBC and Met Office forecasts, England may have one more mini heatwave to look forward to before autumn.
London could see temperatures over 20C from September 14 to September 22, forecasters have said.
Parts of the south and south-east are also expected to stay dry with sunny spells.
But the Met Office said the north and north-west will experience more unsettled conditions, with rain and clouds.
UK Weather Forecast
Today
Some low cloud and hill fog to start then rather cloudy, although a few sunny intervals. Showers could occur almost anywhere but will be heaviest and perhaps thundery in northern and eastern parts. Rather warm and humid in brighter areas.
Tonight
Showers dying out for many areas, though a few coastal showers persisting in the west. Parts of the north and east of Scotland seeing some heavier, more persistent rain. Mild.
Saturday
Showers for most areas lighter and more scattered, with a little more sunshine expected in some areas. A few heavy showers and possible thunderstorms across northern areas of Scotland.
Sunday to Tuesday
Rain in the northeast, otherwise largely dry with sunny spells and the odd shower elsewhere on Sunday. Becoming unsettled from the west from Monday, with thunderstorms Tuesday. Temperatures near normal.
