Drivers have been warned to expect widespread fog across South Yorkshire on Saturday morning.
The Met Office has issued a ‘yellow warning’ for the region from between 1am and 11am tomorrow.
A spokesman said visibility may fall below 100m in some places.
He said: “Patchy fog is expected to develop across much of England during the early hours of Saturday, becoming fairly widespread within the warning area by Saturday morning, with the visibility falling below 100 metres in places and leading to difficult driving conditions.
“The fog will thin and lift slowly later in the morning.”
The conditions are being caused by a ridge of high pressure across much of the UK.