The coldest night of the year so far has led to fresh disruption as flights were cancelled, schools remained closed and drivers faced lengthy delays.
Vast swathes of the country fell below freezing on Tuesday night – with minus 13C (8.6F) recorded in Shropshire – and forecasters warned of another “chilly” night to come.
At least 16 flights from Heathrow were cancelled on Tuesday as airlines continued to recover from disruption caused by heavy snow.
The UK’s busiest airport said its runways were open and fully operational.
British Airways said it planned to operate a “near normal schedule” on Tuesday but passengers due to fly to or from Heathrow were given the option of a full refund or re-booking for travel until December 18.
Passengers travelling on Eurotunnel Le Shuttle services in both directions between Folkestone and Calais faced estimated delays of up to six hours after “horrific” weather conditions damaged the power supply, particularly on the continent, the company said.
AA president Edmund King said Tuesday was expected to be “extremely busy” as freezing temperatures cause “even more hazardous conditions on already wet and slippery roads”.
He urged drivers to take emergency provisions such as chocolate bars, water, a torch and a shovel in case of a breakdown.
The AA recorded its busiest day of the year on Monday with 24,000 callouts.
Rail operators did not report any major disruption due to the cold weather on Tuesday, although delays and cancellations across the South Western Railway network were expected to continue until 4pm following a trackside fire at London’s Waterloo station on Monday.
Clear skies overnight saw temperatures plummet below the minus 12.4C (9.6F) low recorded on Saturday night – with the Met Office recording a new low in Shawbury, north east of Shrewsbury.
In Shropshire, more than 140 schools were closed on Tuesday, while 106 remained shut in Staffordshire and dozens in the South West, West Midlands and Wales.
The Met Office has issued a yellow weather warning for ice until 11am on Wednesday, covering large parts of the country, including the Midlands, Northern Ireland, Wales, the eastern coast of England and parts of Scotland.
Met Office spokesman Oli Claydon said: “It will be a chilly night ahead but probably not quite as cold as last night.
“The front moving from the west hails some more milder temperatures. So in the South West, places like Bodmin, there could be 6C or 7C, so not freezing, but as we move further east London could go down to 2C.
“And as we go into areas where snow remains, like Birmingham, it is struggling to get above freezing today and could be minus 2C overnight.
“There’s still a little bit of snow around so that could melt away or freeze again and there is rainfall coming in from the west, so where that falls on very cold roads that can form ice very quickly, providing treacherous driving conditions.
“It’s a bit of a grey morning tomorrow morning and it will be falling as rain rather than snow, with the exception to that being in high areas of Scotland. We might see wintry showers at lower levels but nothing that’s going to settle.”