Airports across UK including Europe's busiest, Heathrow, have been forced to cancel dozens of flights as ice and thick fog descended on the country overnight.
Heathrow Airport had around 60 cancellations affecting incoming and outgoing flights throughout the day, as well as many more delays, according to its website.
The airport, the busiest in the EU by passenger traffic, began reporting flight cancellations last night and has cancelled more this morning.
A spokesman said last night, "It's better to cancel flights when there's fog because in fog you can't land as many planes per hour because you have to leave more space between the planes."
The spokesman added that cancelling in advance helped airlines accommodate passengers on other flights.
Cancelled flights included scheduled trips to Warsaw, Nice, Stockholm, Aberdeen and several German cities.
London City Airport also cancelled six early morning flights to European cities, including Edinburgh, and reported a number of delays on its arrivals board.
A message on the airport's Twitter page said, "Visibility has not improved, flight disruptions are present and expected to continue until further notice. Please call your airline for info."
Large swathes of the country will be affected by thick fog and freezing temperatures, which have largely affected the north midlands, and central and southern England.
There are also warnings for road users.
The mercury plummeted to minus 10 degree Celsius in Tulloch, Scotland, while Chesham in Buckinghamshire endured temperatures as low as minus 8.7 degree C overnight.
A light dusting of snow and wintry showers will lash the coast today along Kent, Sussex, Hampshire, Devon and Cornwall, while other areas will experience snow-like grains which have formed in the freezing fog.
Nick Prebble, a forecaster for MeteoGroup, the weather division of the Press Association, said, "The thick fog should linger through the morning and into the afternoon."
"It will be a bitterly cold day wherever you are in the UK, and very grey where the fog lingers," he said.
"Northern England and parts of Wales are unlikely to see temperatures above freezing today, and will stay around 4 degree C to 6 degree C in southern England," he said.
He also warned of ice hazards in spots which saw rain yesterday, including north-east coastal areas and Kent.