Temperatures could plummet as low as -8C this week with 70mph storms and an Arctic blast set to dump at least two inches of snow.
Britons have been told to brace themselves for a plunge in temperatures as freezing gales, rain and hail showers batter the nation.
While many people enjoyed a relatively mild weekend, with highs of 12.4C (54F) in South Wales on Sunday, the weather will become far more wintry by Wednesday.
The Met Office predicts the balmy weather will be replaced by rain and strong winds - then temperatures will really plunge and much of the country will see snow on Friday.
Spokeswoman Nicola Maxey told the Daily Express: 'It will turn cold from Friday as an Arctic Maritime air mass moves over the country.
Ms Maxey also said that high tides along the east coast of the country could bring waves crashing over sea walls.
By Friday, the cold is expected to be felt across most of Britain, with hail, sleet and snow all forecast. The showers will spread across most parts of the country, with snow possible in many places even at sea level.
The coldest temperature last week was -6C (42.8F) in Pershore, Worcestershire, on Thursday. The coldest night of autumn, which ended last week, was Saturday, November 25 when Topcliffe in North Yorkshire fell to -6.3C (20.6F).
The coldest night of 2017 so far was January 30 when Braemar, Aberdeenshire, fell as low as -10.1C (13.8F).