Temperatures are forecast to hit 22C by Saturday, fully seven degrees higher than what is expected for the second half of September.
But a former hurricane could be waiting in the wings for the beginning of next week.
Oli Claydon of the Met Office said: “Warm air is being brought up from the continent.
“Southern and eastern parts of Scotland will be the first areas to see the good weather arrive on Thursday.
“By Friday, it’s looking good for everyone. Temperatures should reach 21C in Glasgow on Friday and 22C on Saturday.”
Just this week, Scots had been cranking on the heating as cool autumn air swept across the country.
On Monday, the Aberdeenshire community of Braemar witnessed an air frost after the mercury dropped just below zero, at 0.1C.
Tonight, the mercury will drop to 6C in towns and cities and even lower in sheltered, rural, spots.
Mr Claydon of the Met Office said the approaching heatwave would be short-lived, with cloud increasing from the west on Saturday afternoon and rain by evening.
Again, eastern parts will hold on to the good weather for longest.
But a hurricane could produce a glancing blow by Tuesday.
Hurricane Umberto is the third event of the current hurricane season in the Atlantic, crossing the ocean at 100mph, 525 miles west of Bermuda.
Its current track shows it heading towards the UK by the start of next week but the Met Office is confident it will pass to the north.
Following a Met Office briefing on the matter, Nicky Maxey said: “We are looking at a degree of uncertainty for the north of Britain at the start of next week.
“The rain which we will see late on Saturday and on Sunday is not associated with Umberto. It is purely another low pressure system.
“It has the benefit of pulling up air from the continent, which is why we are getting the hot weather for the start of the weekend.
“Umberto is forecast to pass to the north of the UK, possibly on Tuesday, and it may be it will provide a glancing blow to the north of Scotland.
“There is still some energy within it but in reality, it should be no more than a wet and windy day.”