Temperatures plummeted to -10C in Tulloch, Scotland, while Chesham in Buckinghamshire endured temperatures as low as -8.7C overnight.
A light dusting of snow and wintry showers are expected to greet the coast today along Kent, Sussex, Hampshire, Devon and Cornwall, while other areas will experience snow-like grains which have formed in the freezing fog.
Clear skies and light winds are a recipe for fog to develop, so allow extra time to defrost your car and check before you travel.
It's another bitterly cold day today. It's all down to where the air originates from - and today's can be traced back to Russia.