Large areas of Britain were brought to a halt today as the big freeze tightened its grip on the nation.
Two major airports - Edinburgh and Gatwick - were closed this morning, with motorists and rail passengers also experiencing severe disruption.
Temperatures fell as low as nearly minus 20C in the Scottish Highlands overnight - minus 19.8C was recorded in Altnaharra - and thousands of children were expected to stay at home again due to school closures.
Around six inches (15cm) of snow is expected on higher ground, with strong 30mph north-easterly winds making the temperatures feel as low as minus 7C in parts of the UK.
Forecasters warned that the onslaught of Arctic weather will not show signs of letting up until Friday.
Met Office forecaster David Price said: "It will remain bitterly cold today with the strong north-easterly winds continuing to bring snow showers and making temperatures feel as low as minus six or seven degrees.
"There will be fresh snowfall across the majority of the country, with the only areas really escaping being the Midlands, the far south west of England and the west and north-west of Scotland."
Mr Price predicted that an average of between 0.8in (2cm) and 2in (5cm) of snow will fall across the UK today, with 4in (10cm) to 6in (15cm) falling in higher areas. Temperatures are also expected to struggle to get past freezing, with maximums of just 2C.
He said the snowy conditions will continue throughout tomorrow, adding to the existing levels that have accumulated over the past week.
"On Friday we should expect a reprieve from the showers. However, it will remain extremely cold and the snow will be back over the weekend," added the weather expert.
Severe weather warnings were in place for the whole of Scotland today, with widespread icy roads and heavy snow expected in central and south westerly areas.
Warnings were also in place for northern England, the south coast and parts of Wales.
Gemma Plumb, forecaster for MeteoGroup, the weather division of the Press Association, said snow drifts were reported in East Anglia and Suffolk this morning as a result of the strong winds.
Gatwick Airport was closed today with all departures and arrivals halted until further notice.
Airport spokeswoman Sarah Baranowski said the runway was closed at 10.30pm last night and ground staff working throughout the night had not been able to clear the settling snow.
"It is vital that passengers do not make their way to the airport and check our website and with their airline for updates," she said.
"We need to make sure the runway is safe before all flights can recommence but the snow has not stopped all night."
It is not known when the airport will reopen.
An updated statement on Gatwick Airport website said the runway would remain closed for snow clearance until at least 11am.
"Due to the current weather conditions, all departing and arriving flights at Gatwick are severely disrupted," it said.
"The runway will remain closed for snow clearance until at least 1100.
"Passengers should not set out for the airport and should check directly with their airline for the latest information."
Edinburgh Airport also closed due to heavy snow showers overnight.
A statement on the airport website said it was expected to reopen at 6pm.
Yesterday, commuters worked from home, thousands of children could not go to school and motorists faced travel chaos as a number of roads were impassable.
Hundreds of motorists were left stranded overnight as the weather conditions disrupted road networks.
One of the worst hit areas was Kent, with ice and snow causing hazardous driving conditions and congestion throughout the early hours.
Motorists faced massive delays on the A2 at Cobham after a lorry jackknifed under the M25 flyover.
The Dartford River Crossing was closed, with traffic being diverted through one of the Dartford tunnels.
Kent Police advised motorists not to travel today unless their journey is absolutely essential, saying some roads in the west and north of the county were impassable due to snow and ice.
In Surrey, a jackknifed lorry on the clockwise carriageway of the M25 led to heavy delays near Godstone, while a section of the southbound M3 was closed.
The A2022 was also blocked in both directions in Banstead due to lorries stranded in the snow.
Driving conditions were described as hazardous with the AA receiving an average of 1,350 calls an hour. The RAC said callouts to breakdowns peaked at 2,000 an hour. London was the worst area affected yesterday, with more breakdowns than any other part of the UK.
This morning, Surrey Police advised motorists to avoid the clockwise section of the M25 between junctions six and eight and the anticlockwise section between junctions nine and seven due to congestion which had built up overnight.
Train services all over the country have also been badly affected by the severe weather, with some services not operating and others being badly delayed.
Southeastern rail network faced severe disruption and delays today with a contingency timetable put in place.
The Association of Train Operating Companies (Atoc) said that, as of 5pm yesterday, 73% of trains were arriving at their destination on time.
Insurer RSA estimated that the freezing weather conditions could cost the UK economy up to £1.2 billion a day, with retailers and the restaurant and bar industries likely to be the worst affected.
RSA director David Greaves said: "Bad weather in the run-up to Christmas will have a major impact on the UK's economy and could lead to significant losses for already struggling businesses."
But Halfords said an additional 16,600 sledges were being shipped in from across the globe to meet the demand of excited children.
Southern Railway was operating a revised timetable today, and reported delays between London and Brighton in both directions due to a train which had failed due to an iced conductor rail near Gatwick.
Services were also not running between Redhill and Reigate and Redhill and Tonbridge due to signalling problems.
In South Yorkshire, heavy snowfall that began yesterday evening and continued throughout the night resulted in widespread disruption across the region.
Around four to 10 inches (10-25cm) of snow fell generally, and up to eight to 12 inches (20-30cm) on high ground, and Sheffield City Council said the conditions of the roads and footways were "bad, if not worse, than at any time last winter".
Parts of the county were brought to a standstill, with around 300 schools closed and bus services suspended in Sheffield, Rotherham and Doncaster.
South Yorkshire Police advised motorists to stay off the roads as they tried to deal with several incidents in the area.
A force spokeswoman said: "Police 4x4 vehicles were out overnight trying to assist with clearing roads and dealing with yesterday's gridlock as cars struggled to move anywhere.
"Sheffield City Council has been out this morning attempting to clear tram routes, some of which are running limited services."
There was also disruption to flights at Robin Hood Airport and passengers were advised to check with the airport before travelling.
Humberside Police urged motorists not to drive unless absolutely necessary.
A spokeswoman said the force had experienced a significant number of calls regarding the weather and asked people to call only if absolutely essential.
She said: "The weather conditions have left a number of roads difficult and with poor visibility in some places.
"Rural roads, especially in north Lincolnshire, have been badly affected."
There were no reports of any major incidents but the A164 and routes around Bridlington experienced problems this morning and were described as having poor driving conditions.
Only one lane on the Humber Bridge northbound was open to traffic.
Almost 300 schools across East Yorkshire and northern Lincolnshire were closed today.
Freezing conditions and heavy snowfall caused more problems on the roads across North Yorkshire.
More than 100 schools were closed and roads in the county, which included the A1 into and out of York and various roads around the city centre, all experienced problems due to snowfall.
In West Yorkshire, more than 100 schools closed and there were travel problems across the region, with Northern Rail suspending its train services between Leeds and Sheffield.
A severe weather warning for Yorkshire and Humber remains in place.
In Kent, commuters who battled into work were urged to leave early to ensure they are not stranded amid warnings from police that conditions are set to worsen by mid-afternoon.
Mid and North Kent in particular were set to receive further heavy snowfall as more than 240 schools, nurseries and colleges in the county and Medway closed due to the icy weather.
The new Sheppey Crossing, which closed last night, reopened at 4.10am but Kent Police urged drivers to travel only if "absolutely necessary".
Chief Superintendent Alasdair Hope, of Kent Police, said: "People should consider their safety and decide if their journey is really necessary.
"If you do travel, make sure you have the right provisions for emergencies, and if you are already at work you should give serious consideration to getting home before conditions get worse this afternoon."
In West Sussex, people who venture out are being warned by fire service officials to stay away from areas of frozen water.
In the past decade, more than 20 people have drowned in the UK because they walked on to frozen ponds and lakes, many to rescue people or dogs.
Neil Graham, of West Sussex Fire and Rescue Service, said: "People should take extra care around the edges of waterways because a layer of snow can easily disguise thin ice underneath."
In East Sussex, almost 90 schools were closed and in West Sussex more than 80 schools were shut.
Kent Police said the volume of calls due to the snow was "exceptionally high".
Yesterday the force contact and control centre in Maidstone took 1,298,999 calls and a further 3,419 to the switchboard, making it busier than last New Year's Eve.
Chief Inspector Simon Black said: "The number of emergency calls we received yesterday was almost double the number we would anticipate on a 'normal' day.
"Our call handlers are working exceptionally hard to ensure that calls are answered as soon as possible and that we get help as soon as practical to those who need it.
"As ever, our advice is to avoid travelling unless you absolutely have to and if you do have to travel, then to take all the precautions we suggest around planning ahead for your journey."
Members of the public are advised to call 999 only if a crime is in progress or life is in danger.
In Brighton and Hove, refuse and recycling staff were pulled off their rounds to help grit the city.
Trains on busy commuter routes into London from across southern England were delayed or cancelled, with some having fewer coaches than normal, leading to massive overcrowding.
At Clapham Junction, one of the busiest stations in the country, virtually every train to and from the capital was delayed, some by more than an hour.
Surrey Police urged drivers to make only essential journeys.
A spokesman said the M25 in the county was heavily congested overnight but traffic was flowing again.
Some surrounding roads, including the A22 and the A217 towards Reigate Hill, remained extremely icy and should be avoided.
Hampshire and the Isle of Wight largely avoided the snow, but conditions on roads in the north of Hampshire were icy, police said.
A motorcyclist was killed in a crash involving a lorry in Crawley, West Sussex, at 5.10am today.
It happened near to the A264 and A23 link road at Broadfield South. Police have not disclosed whether the icy weather conditions affecting the area played a part in the crash.
Emergency services helped free the motorcyclist, who has not been named, from underneath the lorry but he was pronounced dead at the scene.
The lorry driver suffered shock but was unhurt, a police spokesman said.
The road was closed but the westbound carriageway reopened just before 7.30am.
A woman has died after falling into a freezing lake at Pontefract Racecourse, West Yorkshire today.
The woman was pulled from the lake and taken to Pontefract General Infirmary where she died, a police spokesman said. The area was cordoned off for it to be examined.
The circumstances of the death are being investigated, but the death is not being treated as suspicious, police said.Reuse content