Britain is set to bask in temperatures far above the seasonal average this week, with the mercury expected to hit 18C by Wednesday.
Parts of the UK will be hotter than Istanbul as warm air sweeps in from the continent.
The Met Office forecasts temperatures will peak midweek, significantly exceeding March's average of 9.2C.
This unseasonable warmth comes as high pressure remains "fairly in charge" over the UK, bringing settled conditions to most areas.
London and the southeast can expect highs of 17 to 18C on Wednesday, when temperatures are forecast to peak
MET OFFICE
London and the southeast can expect highs of 17 to 18C on Wednesday, when temperatures are forecast to peak.
Further north, Manchester, Sheffield and Liverpool will enjoy warm conditions between 13 and 15C.
Even Scotland will feel the warmth, with temperatures set to remain above 10C - still notably higher than the March average.
Skies are expected to stay largely clear across the country, with only a hint of cloud in western areas on Monday through Wednesday.
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The shift in weather patterns is due to changing pressure systems, according to Met Office meteorologist Stephen Dixon.
"Over the coming days, high pressure is going to remain fairly in charge over the UK, keeping things fairly settled," he said.
"As we go into next week, that high pressure begins to move towards the continent and that allows us to start to drag in some warmer air from the near continent, especially as we move into Wednesday and Thursday."
Meanwhile, Istanbul is set for a dramatic temperature drop after experiencing scorching 25C heat this weekend.
The Turkish city will plunge into single digits from Tuesday onwards, with cloudy weather replacing the recent warmth.
By Wednesday, when Britain enjoys its peak temperatures, Istanbul will be shivering at just 6C under grey skies.
This unusual weather pattern means parts of the UK will be significantly warmer than the normally milder Mediterranean climate.
The short-term forecast shows many areas staying dry tonight with clear spells and light winds.
This unusual weather pattern means parts of the UK will be significantly warmer than the normally milder Mediterranean climate (Stock Image)
GETTY
Southern parts of the UK may see frost developing, with mist and fog patches possible under clear skies.
Sunday will bring a bright start with some cloud developing and a few light showers possible, mainly in the northeast.
Monday will be cloudy for many with showers in the south and west, while Tuesday and Wednesday turn dry and sunny.
Overnight frost and fog will continue, but temperatures will rise noticeably by Wednesday.
