Parts of the UK will feel colder than the Arctic Circle in the coming week as bitter winds make it seem like -15C in some places.
Widespread snow is forecast and warnings are in place across Monday, Tuesday, Wednesday and Thursday as the Met Office forecasts a period of "exceptional weather".
Freezing temperatures throughout the week mean the majority of the UK is likely to face disruption on the road, trains and in the air.
More than 20cm of snow could fall in parts of eastern England, Scotland and Northern Ireland, forecasters predict.
Snow warnings are currently in place across eastern England on Monday, all of England, Scotland and Wales on Tuesday, most of the UK on Wednesday and Scotland and the south-west on Thursday.
Meteorologist Charlie Powell said: "The UK is on track for some really cold weather this week.
"It's not going to be record-breaking, but it'll be pretty exceptional - winds are going to make it feel minus 10C to minus 15C during the day.
"We will see the first signs of that tonight in the shape of snow showers working all the way down the east coast."
He added: "Unusually for Britain, the snow is going to be quite dry, so it will blow around and gather in drifts and we could see some blizzard conditions.
"We don't want to scare people, but people should make sure they are prepared for some seriously cold weather."
Temperatures in the UK could plummet so low that they rival those predicted for northern Norway and Iceland.