Snow and ice are expected to cause more disruption in parts of the UK as temperatures plunge overnight.
The Met Office has issued an amber warning in northern England for Friday morning with heavy snow predicted around the southern Pennines.
A wider yellow warning for snow is also in place for Northern Ireland, parts of England and southern Scotland.
The Met Office warned the country could see the "coldest night of the year so far" in rural Scotland.
A spokeswoman said: "The coldest temperature we have seen this year is minus 13C in Scotland, and we are likely to see temperatures slightly below that."
Highways England has issued a severe weather warning and said it expects snow to affect the road network during Friday morning.
Road users in the north of England and northern areas of the Midlands are advised to check road conditions before travelling.
Snowfall of 5-10 cm is expected in parts of northern England, with up to 15cm possible over higher ground.
The amber warning is in place between 04:00 GMT on Friday until 11:00 GMT. The Met Office said delays to road, rail and air travel were "likely" and warned of possible power cuts.
A yellow warning for ice on Friday has also been issued for large parts of the UK, northern Scotland and Northern Ireland.
Meanwhile, in Manchester, the Mancunian Way, a two-mile stretch of elevated motorway, was closed in both directions on Thursday morning, following a crash involving four vehicles.
There were no reports of any serious injuries in the incident.
However, with the weather set to worsen in the region, Greater Manchester Police advised people not to travel "unless absolutely necessary".
Flights were expected "to operate as scheduled" at Stansted Airport on Thursday, after "adverse weather conditions" forced dozens of flights to be cancelled or delayed on Wednesday.
Passengers, many of whom were obliged to sleep in temporary beds at the Essex airport overnight, vented their frustration on social media.
Incredibly the 5 hour delayed FR8545 from Berlin to @STN_Airport has landed at 03:12, but has been sitting on the tarmac for 40 minutes as no-one is available to offload it. Excellent coordination @Ryanair and Stansted Staff.
— Joe Allen (@jsjallen) December 28, 2017
End of Twitter post by @jsjallen
Luton Airport said it was open and the runway "operational", but flights "may be subject to delay" and passengers should check with their airline.