The yellow (be aware) warning is from 3pm today until 11am Christmas Day.
The Met office says: “Fog or freezing fog patches will quickly become more widespread later on Christmas Eve, and will also be dense in places.
“Not everywhere will see fog, but where it does form, the visibility may fall to around 50 metres at times.
Fog will tend to thin and lift in western and some central areas of England overnight, but will be slow to clear on Christmas Day in the east, perhaps persisting for much or all of the day in parts of Eastern England.”
The rest of Christmas Day and Boxing Day look likely to remain cloudy.