A “mini Beast from the East” has brought freezing winds from Scandinavia and Siberia and sent temperatures plummeting
A “risk to life” weather warning has been issued for the south west of England, where up to 12.7 inches of snow has fallen.
Yellow weather warnings for snow and ice are also in place across most of England and Wales, south-west Scotland and parts of Northern Ireland.
More than 10,000 passengers are stranded at Heathrow Airport after 146 services were cancelled.
British Airways halted 64 short-haul flight and trips to the US.
Are Lingus cancelled trips to Belfast and Dublin and Lufthansa stopped flights to Frankfurt and Munich.
British Airways said in a statement: “We have merged a small number of flights travelling to or from Heathrow Airport.
“During cold weather conditions, aircraft have to be de-iced prior to departure to ensure that they are safe, and additional measures are taken to ensure the safety of our operation is maintained at all times.”
Snow has also coated roads across the UK – trapping motorists overnight and rendering driving impossible in parts today.