An atmospheric-pressure battle will bring spring sunshine to half of the country this week while winter clings on elsewhere.
High pressure wedged over Scandinavia will tussle low pressure skimming the UK south coast, creating a countrywide weather split.
Temperatures in the southwest will hit double figures by mid-week as a North Sea wind wafts chilly gusts to the north-east, and the risk of snow.
Met Office meteorologist Aidan McGivern said: “A marked temperature contrast starts to form through Wednesday, Thursday, and Friday.
It will be chilly to the northeast, milder to the southwestNETWEATHER“We are going to see six or seven Celsius and a brisk wind coming in from the North Sea for the northeast of the UK and that is going to make it feel chilly, but in the south and southwest, 12C and 13C will be much more pleasant with sunny spells.”
High pressure will fend off lows trying to push in from the Atlantic, bringing largely dry weather for many parts of Britain.
Eastern regions will stay cooler, cloudier and foggier this week, while the south and southwest enjoys the best of the sunshine.
McGivern said: “On Thursday, for many it is going to be a dry day, and again with that temperature contrast with 13C in the south and southeast, and 7C towards the northeast, feeling cold in that wind coming in from the North Sea.
“Showers could fall as snow with the cold air in place over the Pennines and the Scottish mountains.
“Where we do get some sunshine in the southwest it will feel positively spring-like, but in the northeast, more like a continuation of winter.”
It comes as England and Wales records the warmest February on record, according to Government figures.
Last month hit an average of 7.5C, beating the 7.0C recorded in 1990, making it the second warmest February for the UK as a whole.
Southern Britain saw the highest temperatures, which hovered around 3C above normal for the time of year.
Met Office senior scientist Mike Kendon said: “Despite a cold spell in the north in the first half of the month, the main theme of February is how persistently mild and wet it has been, particularly in the south.
“This is largely due to the influence of Atlantic low-pressure systems bringing a predominant mild, south-westerly flow.”
Easterly winds in parts of the country this week will bring a sharp contrast, however, with snow possible over the Scottish hills.
Jim Dale, meteorologist for British Weather Services and social commentator, said: “Although it is not unusual for this time of year, there is going to be a brisk easterly in parts of Britain through the middle of the week and into the weekend.
“This will make it feel chilly in the north and the east, while in parts of the south it won’t feel too bad.”