The Met Office has launched three weather warnings across large swathes of the UK.
Snow forecast for areas from northern Scotland to the Home Counties about the freezing wintry conditions.
Temperatures plummeted overnight, with a low of -13.5C (7.7F) recorded in the Highland village of Dalwhinnie, while freezing temperatures were recorded as far south as London Luton Airport.
In Northern Ireland, yellow “be aware” warnings are in place for both rain and ice.
The Met Office warned already-icy surfaces could become even slipper as rain falls on to freezing cold surfaces. It said: “This could lead to some injuries from slips and falls on icy surfaces.”
Icy patches are likely on some untreated roads, pavements and cycle paths – while some disruption could be seen to journeys by road, bus and train on affected routes.
Traffic Scotland urged drivers to check their routes before setting off and to ensure they were carrying emergency supplies in case they get stuck.
North Wales Police also warned of poor conditions on the roads due to snow and ice, particularly on routes in Snowdonia.
The Mountain Road was closed on the Isle of Man due to snow.
It also warned heavy rain, combined with the possibility of melting snow, could lead to some surface flooding and transport delays.
Temperatures could also plunge to -11C.
Snow is more likely to affect higher areas such as the Highlands and the Welsh hills, as well as the north of England.
The forecast explains: “The snow is expected to become confined to northeast Scotland later in the day as it progressively turns to rain from the southwest.”
In areas of the UK where snow is not expected, it’s thought Sunday will be characterized by heavy rain.
On Friday, drivers were urged to stay off the roads unless absolutely necessary, with higher amber weather warnings across the north of the UK.
Dozens of schools were closed around Scotland, while others shut early as the heavy snowfall continued.
While on Saturday motorists were warned again to be wary of ice on the roads after disruption plagued the UK all week.
Police warned skiers heading to resorts not to park on the verges after disruption on Saturday and warned that cars causing obstructions may be seized.
Skiers faced six-mile tailbacks as they flocked to the slopes at Glencoe Mountain Resort to take advantage of the snowy conditions.
Drivers abandoned their cars on the roads as they tried to reach the resorts where car parks were full and police said high volumes of traffic hampered the efforts of gritters.
Saturday night saw the coldest temperature recorded in the UK since February 14 2016, when minus 14.1C (6.6F) was recorded at Braemar.
Image Source: Kyodo