Snow and ice are expected to hit London and southeast England this weekend, causing disruption for rail drivers and passengers.
For Sunday, Met Office experts have issued a yellow warning – the third highest – for areas of the UK usually least affected by freezing temperatures.
They said snow could fall in parts of east and south-east England, leading to a risk of disruption to travel, especially on Monday morning. Cell phone coverage may even suffer, forecasters warn.
The UK woke up to a bitter cold on Friday, with temperatures as low as -8C overnight.
Colder weather is expected over the weekend, with the thermometer expected to stay just above freezing on Saturday before plunging again, and snow and ice warnings remain in place across the UK.
Forecasters said snow and ice will make travel across central and southern Scotland difficult on Saturday evening, overnight and Sunday morning.
In southeast England on Sunday, the Met Office warns of a small possibility of travel delays on the roads, with some vehicles and passengers stranded, along with delayed or canceled rail and air travel.
“There is a small chance that some rural communities could be isolated,” the forecaster warned.
“There is a small chance that power outages will occur and other services, such as cell phone coverage, may be affected.”
They also warned of injuries from slips and falls on icy surfaces and the risk that untreated sidewalks and cycleways could become impassable.
Schools were forced to close in Scotland on Friday after temperatures of around -8C to -9C were recorded in rural areas overnight from Thursday to Friday.
South East England suffered its worst heatwave on record in the summer.
PROSPECTS OFFICE MET
Friday night and tonight:
The winter showers continue along the exposed coasts, with some further accumulation on the hills and risk of frozen surfaces. Clear elsewhere and widespread frosts, intense in some areas. Some freezing fog forming in places.
Cold with widespread frost and some patches of freezing mist at the start, slow to clear in places and quick to reform thereafter. More winter showers for the exposed coasts. Mostly light winds.
Outlook from Sunday to Tuesday:
The cold continues, with sunny spells and winter showers, mainly close to the coasts. Severe night frosts and patches of freezing fog. Winds starting off light but strengthening through Monday and feeling very chilly.