Thick fog is expected to blanket much of the UK overnight and beyond rush hour on Tuesday morning.
The Met Office has issued a yellow weather warning for fog which could freeze in some places and disrupt transport, covering most of England and the eastern edge of Wales.
Encompassing most areas south of Scarborough and east of Manchester in the north, and east of Exeter in the south, the warning is in place from 7pm on Monday until midday on Tuesday.
Temperatures are also set to dip to near 0C (32F) overnight for many areas, meaning the fog could freeze on some roads.
Met Office forecaster Craig Snell said motorists should allow extra time for their journeys.
He said: “The fog is going to be most widespread in southern, eastern England, into the Midlands and the east side of Wales too.
“Not everywhere within that warning will be foggy, but the main message to drivers is to allow some extra time for your journey because there could be fog around.
“It could have a knock-on effect on public transport, so there could be delays to bus journeys and train journeys.
“The fog will tend to clear as the morning goes on.
“It may linger on in a few spots, but towards lunchtime conditions should be much better.”
Mr Snell added that a combination of long winter nights, clear skies and still air can cause fog to settle.
“When the air is quite still, there’s nothing to move the fog around so that’s why it becomes dense,” he said.
“This time of year, our nights are long so we don’t have the heat from the sun, and the ground starts to radiate heat from the surface.
“This creates a long period of cooling.
“It’s a mixture of clear skies, light winds and long nights.”
Meanwhile, patchy sunshine and cloud is expected in Scotland and Northern Ireland.
The Met Office has said temperatures are around average for the time of year, with overnight temperatures of 3C (37.4F) predicted in Edinburgh, 2C (35.6F) in Belfast, 1C (33.8F) in London and 0C (32F) in Cardiff.
On Tuesday, the mercury is set to rise to around 7C (44.6F) in London, 8C (46.4F) in Edinburgh and Cardiff, and 9C (48.2F) in Belfast.