Britons are being warned to get their jumpers and scarves back out after one of the warmest Marches on record melted into predictions of snow and sub-zero temperatures.
Sun worshippers have basked in glorious weather during the last few weeks - seeing the sunniest March in more than 80 years.
But after Britons opened up their summer wardrobes, temperatures are now set to dip as low as -7C in parts of the UK.
Despite a new March Scottish temperature record of 23.6C being set last week in Aboyne, Aberdeenshire, the snow is forecast to begin falling tonight with most areas expected to see between 10-15cm - with 20cm predicted over high ground.
And the big chill is not just restricted to north of the border.
Snow and a big freeze will grip parts of England from Tuesday night going into Wednesday.
Nick Prebble, a forecaster with Meteogroup, the Press Association's weather division said the dramatic change in conditions and temperature was caused by a big ridge of high pressure over the UK dragging warm air up from the south, giving very warm temperatures for the time of year.
But a band of rain with very cold air going southwards across Scotland will deliver snow and a huge fall in temperature.
Tomorrow's temperatures in northern Scotland will range from 2 to 5C with minimums of -6 to -7C.
Mr Prebble said: "By 6am tomorrow snow will be in the central belt of Edinburgh and Glasgow and only very far southern parts of Scotland will escape the snow until dawn but it will spread to all areas by 9am.
"Central areas will see between 10 and 15cm of snow, localised hill areas could see up to 20cm.
"The weather will gradually reach across northern England and through the course of the day many areas will see rain showers starting in Northumberland and the rest of northern England."
Tomorrow evening the snow is expected to fall through Yorkshire and the north west of England, spreading into the Midlands and Wales.
Mr Prebble said between five and 10cm of snow could fall but the south east and London are expected to escape it.
He said: "Throughout the week temperatures start to recover - it appears to be a fairly short-lived cold snap."
The weather is in stark contrast to March's mini-heatwave - the only years to have a warmer March in the past 100 years were 1938, 1948, 1957, 1990 and 1997.
Paul Mott, senior forecaster at MeteoGroup, the weather division of the Press Association, said: "The weather in March has been quite exceptional. There were a number of Scottish records that were broken and some of the highest temperatures ever recorded in March."