It'll be another very cold night with temperatures a few degrees below freezing.
There'll be a widespread, sharp frost and freezing fog will affect many areas, becoming increasingly extensive.
It'll thicken up enough to bring very poor visibility making for difficult, hazardous driving conditions tonight and into tomorrow.
The fog has already reduced visibility to 100 metres in some parts of southern England, the Midlands and East Anglia - and could pose a problem beyond tomorrow morning.
The frost and freezing fog will cap temperatures all day across central Britain - barely above freezing point for some of us and feeling bitterly cold.
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.