Snow is expected to fall across the UK this week and overnight temperatures will drop.
The Met Office said a “prolonged period” of snowfall at higher altitudes is possible in Scotland and parts of northern England and Wales over the weekend.
It will come after “several shots” of Arctic air over the UK this weekend as the jet stream bends south, bringing much cooler and wetter weather.
The mercury could drop as low as freezing overnight over parts of London and the south east, while it remains around 6C (42.8F) during the day on Saturday.
Are you seeing a change in temperature?
Multiple shots of arctic wind en route to the UK this weekend as the jet stream brings much of the south #cold and wet weather
— Met Office (@metoffice) November 23, 2021
Yellow weather warnings are also in place for parts of Scotland and Northern Ireland on Friday, extending to the rest of Britain on Saturday.
The Met Office said “very windy weather” could cause delays in transport, damage to buildings, the closure of bridges and roads and power outages.
Met Office spokesman Graham Madge told the PA news agency: “We’ve got an unstable period of weather over the next few days, with wind warnings beginning for Scotland and Northern Ireland starting Friday.
“This will extend to the whole of the UK except for London and the South East on Saturday, with strong winds.
“There are increasing signs of snow at higher altitudes, with signs suggesting that areas above 200m in Scotland are most likely from Friday.
“In areas such as the Pennines and Snowdonia there may be intermittent spells in other areas of northern England and Wales, although it is unlikely to be heavy enough for settling.”
He said there were “no signs” of snow in the lowlands of England and Wales, but he said “never say never”.
It comes as a cold front prepares to move over the UK overnight, bringing with it cold but clear conditions.
Mr Madge said: “Friday and Saturday, although bright and clear, will be quite cold with the possibility of prolonged snow at the higher levels, but we are not anticipating anything at the lower levels.
“Although there were not exceptionally cold temperatures during the day, it could be freezing overnight at many places.
“Coldest day temperatures for London and the South East will be around 6C on Saturday, although this is not particularly rare for the time of year.”