The mercury rocketed to 19.6C in Kinlochewe village in Wester Ross, in the Highlands, making it a January record for the UK and a whole winter record for Scotland, according to provisional data from the Met Office.
The previous record for a January day was set in the villages of Inchmarlo and Aboyne in Aberdeenshire which hit 18.3C in 2003, while Aber, in Ceredigion, Wales, reached the same level in both 1958 and 1971.
The high is a result of a rare situation that sees isolated spots near mountains hit with a narrow blast of hot air.
Most of the UK experienced a relatively mild and dry autumn and winter and is currently in the grip of a southerly wind, bringing warm air up from the Azores.
In the more mountainous regions of the north, a phenomenon known as the Foehn Effect has amplified the conditions further.
The effect sees air rise up a mountain, heat up in mild, dry conditions high up, before travelling down the other side of the slope, bringing the extra heat with it.
It is taking the already mild air from off the coast of Africa, heating it even further above the Lochs of Scotland, and then a heated plume is travelling downwards
A fortnight ago Kinlochewe was frozen, with its maximum daily temperature hovering just above zero, at 0.6C. It is now the UK’s hot spot.
Ironically, Sundays provisional data came as meteorologists issued a yellow warning for wind in northwest Scotland, which includes Kinlochewe.
Britain has already been rocked by savage Storm Isha, which rolled in causing carnage across the country.
The freak front was caused by cold Arctic air pushing south into North America making the jet stream, which flows from west to east, more active.
The topsy-turvy weather comes after much of the UK thaws from an Arctic blast which saw sub-zero temperatures earlier in the month.
Storm Isha was the ninth storm to rage into the UK since September and follows Storm Henk, which unleashed New Year misery with gale force gusts and lashing rain felling trees, downing power lines and bringing the travel network to its knees.
2023 was a busy one weather-wise with storms Agnes, Antoni and Gerrit bringing carnage to the UK.
During a bonkers washout summer trees were uprooted and rail services suspended while hundreds of thousands were left without power as 80mph winds battered Britain and 50mm of rain – almost half of the average rainfall for the month – fell in August.
The record number of named storms in one season is 11 in 2015/16.
