Yellow weather warnings are in force for ice, snow and strong winds. Affected areas include eastern, north-west and north-east England, northern and south-west Scotland, the West and East Midlands, Wales and Northern Ireland. The colder conditions follow a short spell of unseasonably mild air.
Commenting on the outlook, Met Office meteorologist Becky Mitchell said: “After a fairly cloudy, wet and reasonably mild day for most of us it is all set to change on Sunday.
“Colder air from the north will sweep across the country bringing a risk of ice and for some of us some snow.”
Britons can expect “blustery and icy winds” to thrash the nation as Arctic air moves south, Ms Mitchell explained.
She said: “Bringing a very, very cold end to this week.”
Temperatures will be “just above freezing” on Sunday morning as westerly winds of up to 60mph buffet the UK.
Ms Mitchell said: “Some slippery surfaces out there first thing and some blustery winds as well.”
Yellow weather warnings are in force for snow and ice in Scotland and for wind in the east and north-west.
The weather expert said: “But as we head into Sunday afternoon the sun will start to come out and it will turn much brighter.
“Mixed in with that brightness there will be a scattering of wintry showers.”
There will also be some “snow at lower levels” in northern parts of Scotland, Ms Mitchell cautioned.
She said: “The winds continue to be strong through Sunday – very blustery particularly in the east – gusts of 60 to 70mph along the coast and that means some large waves.”
The winds will also make it feel “very cold”, Ms Mitchell warned.
She said: “It will feel more like sub-zero.”
The Met Office expert also predicted a “widespread frost” for Monday morning as temperatures plummet.