Travellers face transport chaos on Sunday as a third of flights from Heathrow Airport are cancelled amid forecasts of heavy snow, and freezing conditions create dangerous driving conditions.
The moves comes as forecasters predicted up to six inches of snow and ice this weekend with temperatures falling to -12 and windchill making it feel significantly colder.
Airport operator BAA, Heathrow airlines, and air traffic control agreed to introduce a reduced flight schedule to “minimise the disruption to passengers” caused by severe weather.
However, the airport anticipates more than 70% of passengers will still be able to travel as airlines transfer them between flights.
The Met Office said snow will deliver what is expected to be the biggest and most widespread snow dump of winter.
Saturday is expected to be the coldest day of winter, with -12C temperatures due in the early hours feeling like -15C due to bitter windchill.
Transport chaos is forecast, with widespread ice and snow lying until at least Monday, while weekend sport faces postponements, including football and horse racing.
Portsmouth’s home match against Hull City on Saturday was cancelled due to a frozen pitch. Several matches in the lower leagues were also called off.
Racing was also heavily hit, with the meeting at Ffos Las scrapped on Saturday, while Sandown and Wetherby were cancelled on Friday.
Sunday's meeting at Kempton will be subject to an inspection because of the threat of overnight snow.
The AA said it had been called out to more than 4,300 breakdowns on Saturday morning - around 1,500 every hour - and it expected this figure to reach up to 16,000 by the end of the day, almost double the 8,500 of a usual Saturday.
Twitter users have reported frozen canals and lakes, while other tweeters dug out toboggans ready for a weekend of sledging.
The Met Office said Sennybridge, Powys, dropped to a teeth-chattering -11.3C in the early hours of Friday morning - Britain’s coldest temperature recorded this winter, beating the -10.5C in Aboyne, Aberdeenshire, on January 16.
The sub-zero freeze hit nationwide early yesterday, with Braemar, Aberdeenshire at -10.9C, Benson, Oxon, at -10.8C and Woburn, Beds, at -9.9C.
Some places spent all day anchored below freezing, with Wainfleet, Lincs at -2.5C at 12noon, while other parts scraped 1C or 2C for a few hours before tumbling back below 0C, with snow flurries in the east again.
Friday night was due to see widespread -6C to -8C lows, with a new record winter low of -12C in places, a severe frost and up to two inches more snow from Kent to The Wash.
The Met Office issued an amber “be prepared” warning for today (Sat) for almost all of England bar the south-west and far north, predicting between two and four inches of snow between 12noon and midnight.
Most other parts of England, Wales and southern Scotland are on yellow alert for an inch to two inches of snow.
The snow will start in the west and move east - with all parts including in low-lying areas due to be affected.
A third yellow warning was issued for almost all of England and Wales for snow to continue overnight until tomorrow lunchtime. (Sun)
Independent forecasters Netweather and Weatherquest both predicted up to 15cm of snow in parts of the midlands and east.
Today (Sat) is also expected to be the coldest day of winter, with the Met Office forecasting that most of the country away from the south-west will remain below 0C all day.
The snow is expected to lie until Monday at least, with widespread ice and freezing fog making for nightmare travel conditions.
The Met Office said windchill is making temperatures feel colder than they are - meaning overnight -12C temperatures were feeling like -15C.
Forecasts said windchill will double this afternoon (Sat), taking 6C off how temperatures feel, making most places feel sub-zero as 30mph wind gusts hit England, with up to 45mph on Irish Sea coasts and in Scotland.
Tonight (Sat night) will be less cold at -4C due to cloud cover - but feeling like -10C due to windchill.
Met Office forecaster Dave Britton said: “Temperatures fell to their lowest level this winter in many places on Thursday night.
“Friday night was due to see temperatures fall to -6C to -8C in many places, and perhaps as low as -11C in rural areas. We could even see temperatures as low as -12C.
“Windchill is also affecting how temperatures feel. It affects the body and makes temperatures feel several degrees or more colder than they actually are.”
Netweather forecaster Paul Michaelwhite said: “Snow amounts are likely to peak in central and eastern parts on Saturday night, with 10-15cm possible in places, perhaps more on hills.
“Travel disruption is very likely, although there is uncertainty over which areas are at highest risk.
“At least the snow will encourage people to venture out by sledge rather than by car.”