The Met Office has issued a yellow weather warning for fog, which covers a huge swathe of England and parts of Wales.
Fog is expected to develop through Wednesday evening and overnight – and will be “dense” with “visibility below 100m” in some places, forecasters have said.
The weather warning stretches from Exeter and Cardiff up to Hull, covering cities including Oxford, Peterborough, Birmingham and Lincoln.
The Met Office website states: “Some of the fog will tend to thin and lift into low cloud across parts of southern England and the southeast Midlands by dawn, but is likely to persist in a corridor from southwest England through the rest of the Midlands to Lincolnshire and Yorkshire until late morning.”
The warning is in place until 11am on Thursday.
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Drivers are being urged to check conditions and make sure their fog lights are working before setting out.
Buses, trains, flights and ferry travel could all be affected by the weather, the Met Office has said.
The warning comes just after the end of a cold snap which saw temperatures in the UK drop to almost -20C.
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Temperatures fell to -18.7C in Altnaharra, a hamlet in the Scottish Highlands, on Friday – making it the UK’s coldest January night in 15 years.
Snow has also caused travel disruption travel in the past week. Manchester Airport was forced to close both its runways last Thursday, while roads in Cornwall and Devon were closed.
Hundreds of schools across England, Scotland and Wales were also forced to shut.
