Forecasters have warned the “coldest night of the season” is set to hit parts of the UK, with temperatures dropping to as low as minus 10C (14F).
The warnings, set to last until Monday morning, say people should expect to see “icy patches” on roads and pavements, meaning accidents and slips and falls are “more likely”.
Many parts of the country fell below freezing to around minus 4C/minus 5C (24.8F/23F) overnight, with Shap in Cumbria hitting minus 6.4C (20.5F).
It comes after Storm Arwen wreaked havoc across much of the UK, bringing strong winds, sleet and snow.
Met Office forecaster Tom Morgan told the PA news agency: “As Storm Arwen is clearing out to Europe, a cold northerly flow of wind has been left behind in the UK, causing some of the bitterly cold temperatures we’ve seen.
“There is set to be further wintry weather on Sunday, with snow expected to fall across areas in Scotland and northern England, and even in parts of southern and central England.
“Parts of Scotland and northern England, where snow is on the ground, will be very cold again tonight, with the temperature certainly falling below zero and even as low as minus 10C (14F), which would make it the coldest night of the season so far.
“Though this is expected to be the exception rather than the rule, temperatures of below freezing will be widespread, including in London and the South East which could hit minus 2C (28.4F).
“Even if you do live in a city, you can expect to be scraping frost, ice or even snow off your cars on Monday morning.”
Mr Morgan added that, although frost will also be seen in Wales and Northern Ireland, temperatures there will not fall as low as England and Scotland.
A cold weather alert was issued by the UK Health Security Agency on Friday, remaining in place until Monday, prompting advice to people to try to stay warm and look out for those most at risk from the effects of the chilly conditions such as the elderly and anyone with heart and lung problems.
Mr Morgan said this is due to an “Arctic shot” which has moved south across the UK.
The cold spell comes after three people were killed when trees were blown over by strong winds as Storm Arwen hit on Friday.
Gusts of almost 100mph also caused transport disruption, power cuts and damage to buildings, while heavy snow led to lorries getting stuck and ploughs being used in a number of areas.
Northern Powergrid, which supplies energy to the North East, Yorkshire and northern Lincolnshire, had said 240,000 customers lost service but on Sunday it announced supply had been restored to 200,000.
The company added more than 1,100 instances of damage have been recorded, with more being discovered as repairs continue.