London awoke to a frosty morning as clear skies saw temperatures plunge across the UK.
The icy start came as forecasters warned the mercury could plummet as low as -8C in part of Britain on Saturday night - the lowest of the year so far.
The Met Office has yellow warnings of snow, valid until 7am, for the Highlands, Grampian and the Central, Tayside and Fife regions.
The Scottish Borders recorded temperatures of -2.5C by 3am - and that was with several hours of the night to go.
The current lowest temperature of 2014 is -7.7C n Altnaharra, northern Scotland, in February.
Cold weather - in pictures
Yellow warnings of ice were issued for large swathes of the UK, though much of the south-east escaped without warnings.
Kate Brown, a forecaster at the Met Office, said places with clear skies were hit with the lowest temperatures.
"People will be waking up to those very cold temperatures," she said.
Ms Brown said the "vast majority" of places would be hit with freezing temperatures.
"The places that may escape the worst of it are the places that have been covered in the cloud earlier on tonight so they've had that bit less time to get colder," she said.
Ms Brown said temperatures should rise above zero during the day, with the coldest places managing to get up to 1C or 2C, and clear skies even making way for "plenty of sunshine".
She said "a widespread frost" is likely.
