Snow showers swept the UK this evening as the first widespread big freeze of the winter threatened to cripple much of the country.
With most of the UK on amber alert, the Met Office's second highest severe weather warning, flights were cancelled and a string of sporting fixtures fell victim to the big chill.
It came after Britain shivered through the coldest night of the winter so far with temperatures plunging to minus 12.4C last night and forecasters predicting up to 15cm of snow.
Flurries fell over Scotland, northern England and the Midlands this afternoon with dumps predicted to hit London and East Anglia later this evening.
Most parts of the country are expected to wake up to a blanket of snow tomorrow morning, with 5cm-10cm forecast in many areas.
Up to 15cm of snow is expected to cover parts of Cumbria, Lincolnshire, East Anglia, North Yorkshire, the Peak District and the Midlands.
Some 10cm are forecast to settle at Heathrow Airport where a third of tomorrow's flights will be grounded amid adverse weather conditions and the possibility of freezing fog.
Passengers travelling through Gatwick were warned to expect some disruption and delays, with flight cancellations remaining a possibility.
On the roads, motorists faced what the RAC described as a "dangerous cocktail of driving conditions" and were urged to stay at home where possible.
The Highways Agency extended its amber alert until 9am tomorrow, meaning there was a "high probability" of severe snow and a risk of "adverse" driving conditions.
Kevin Andrews, RAC patrol ambassador, said the wintry weather and sub-zero temperatures had left roads "extremely treacherous".
He added: "It looks like we're going to get a dangerous cocktail of driving conditions this weekend."
The motoring organisation said it had attended 70% more breakdowns than normal while a spokesman for the AA said it dealt with around 1,500 call-outs per hour this morning.
The total figure was predicted to reach up to 15,000 by the end of the day - almost double the 8,500 of a usual Saturday.
The Met Office's amber alert in England applies to Yorkshire and Humber, the West Midlands, East Midlands, the East, the South West, London, the South East and the North West.
A yellow alert, which warns people to "be aware", was in place for parts of Scotland, Wales and south-west England.
Much of England is also under a cold weather alert of level 3, which warns of "100% probability" of severe cold weather, icy conditions and heavy snow.
Forecaster Paul Mott, of Meteo Group, the weather division of the Press Association, said the deep freeze was likely to continue into next week meaning the snow is likely to settle and much of Britain will remain carpeted in white.
"We have got a band of snow over northern England which will move east over the next few hours," he added.
"We will start to see snow over south-east England and London later this evening which will become fairly heavy through the evening and there will be up to 10cm of snow falling quite widely over the South East and eastern England.
"That will clear most areas by about midnight but will hang on over East Anglia until about 9am."
While the mercury dropped to minus 12.4C in South Newington, Oxfordshire, last night - the lowest recorded temperature this season - it is expected to remain considerably milder tonight with lows of minus 3C before falling again next week.
The icy spell has already seen daytime temperatures plummet four or five degrees lower than average for February - traditionally the chilliest month of the year.
The Department for Transport has said it was better prepared than ever for severe winter weather.
Salt stocks across Britain stand at more than 2.4 million tonnes - a million more than last year.
But they were of little comfort to sports fans hoping to see Portsmouth's home match against Hull City which became the first Championship fixture cancelled due to a frozen pitch. The Doncaster versus Reading match was similarly postponed while a number of other lower league contests were called off.
Racing was also heavily hit but the ice did not deter swimmers who plunged into the Serpentine in London's Hyde Park this morning, despite its partially frozen waters.