Temperatures are set to plummet with snow, sleet and hail forecast in parts of Scotland.
A cold weather front will move south across the UK on Friday and over the weekend, bringing cooler air from the Arctic.
Strong winds and gales are predicted in Scotland and forecasters have warned there could also be snow, hail and sleet on high ground.
Motorists have been warned to take extra care on the roads.
Met Office forecaster Bonnie Diamond said: “Especially overnight on Friday and Saturday there is a risk of ice and frost as temperatures fall close to or below freezing.
“Across the north half of the country there is a chance of showers falling as snow on high ground and a mix of sleet and hail, mainly in Scotland.”
She added: “We have had a pretty mild October so far and a warm start to autumn in places so it will be a big change for everybody as we go through the weekend.
“Certainly it’s time to get the warm winter clothes out.”
Gritters are on standby across the country, with a number of councils posting pictures of their fleets online.
Temperatures are predicted to be 7C (45F) in northern England and 10C (50F) in the south during the daytime on Friday.
The last time it snowed in the UK in October was in 2012 when around an inch (2.5cm) fell in some areas of north-east England.