The remnants of Hurricane Gert could divide the country in two by sweeping in to salvage summer for the South but soak the North, according to forecasters.
August's patchy weather so far will continue for those in Scotland, Northern Ireland, and the North of England as the category two hurricane loses strength over the Atlantic Ocean as it rides in on the jet stream.
But for those in southern and eastern parts of the UK, temperatures could soar as the weather system bringing tropical air arrives on Sunday, with the mercury forecast to reach up to 27C in the south east on Monday.
Hurricane Gert, the second hurricane of the season in the Atlantic, is travelling along the eastern coast of the US.
It is expected to move eastwards and become a low pressure system with its centre somewhere between Iceland and northern Scotland, Met Office forecaster Luke Miall said.
He said: "At the moment we might see a bit of a North-South split developing.
"The wet and windy weather will most likely be to the north and west of the UK, so Scotland, Northern Ireland, north west England and North Wales will have a wet and windy weekend.
"Nothing severe is expected but given this August so far, it's just a bit disappointing, since the kids have broken up, it's turned a bit more unsettled."
Temperatures in those regions will likely remain around 18C (64.4F) to 19C (66.2F) on Sunday and Monday, while higher ground in parts of western Scotland and north-western England could see up to 25mm of rain - or a third of a month's rainfall - in a few hours.
In the south and east of England, Mr Miall said: "If we get up to 26C (78.8F) or 27C (80.6F) on Monday that will make it the warmest day of August."
He added there was some uncertainty about where the UK will be split by the weather because it is dependent on whether the hurricane's remains track further south, meaning the rain could reach parts of the Midlands, or further north, extending the warmer patches.
The weather is likely to be more settled by midweek but it is unclear what to expect over the August bank holiday.
Mr Miall said: "It will turn cooler and fresher by Wednesday. It will still feel pleasant in the sunshine.
"It's very uncertain, once this system comes through we will have a lot more confidence about how things will play out."