Brace yourselves for an icy blast – bookies have cut the odds on it being the coldest ever November.
Parts of the UK were covered in snow over the weekend and the Met Office said more is on the way.
Daytime temperatures will rise this week to around normal for the time of year, 10 to 12C (50-54F) in the South and 8 to 10C in the North.
But, the new month will see the nation start to shiver.
Bookies have cut the odds on it being the coldest November on record to just 6/4.
Met Office meteorologist John West said: “Our current guidance is that temperatures are looking like they are going to be below average by mid-November. There is a greater likelihood of some overnight frosts as well as some snow over higher ground in the North.”
Mid to late November usually brings daytime highs of 9 to 10C in the South to around 7C in the north of Scotland.
Forecasters say they expect the mercury to dip one or two degrees below those.
The lowest ever overnight November temperature was -23.3C in Braemar in the Cairngorms, in 1919.
And Halloween trick-or-treaters have been advised to wrap up midweek.
Mr West said: If anybody is going to be out and about on Wednesday, it might be a good idea to have a coat handy and maybe also a waterproof.”
Three-day UK weather forecast
Today (Monday): There will be sunny spells for much of England, Wales and Scotland, but with scattered showers too, though mainly in the east. Some showers perhaps heavy and wintry on the Scottish hills. A cloudier day in Northern Ireland and in the south-east at times. A chilly day. Breezy in the north-west
Tonight (Monday night): Cloud will push in across the east of the UK, becoming breezy here. There will be showers along the east coast, and rain will move in to central parts of the UK and eastern Scotland through the early hours. Mainly dry with clear spells in the north-west, Wales and the south-west with mist in places
UK Outlook (Tuesday and Wednesday): Tomorrow, it will be rather cloudy with outbreaks of patchy light rain over Wales and central England and with sunny spells and showers in the north. Windy along east coasts, where there will also be showery rain. Unsettled and wet on Wednesday with showers or outbreaks of rain, some heavy. Showers could be wintry for a time on the hills of northern Scotland. Breezy in the north-west