Warnings of widespread ice are in place for many parts of the UK, and forecasters say it will continue to be the major problem into the weekend.
Warnings of widespread ice are in place for many parts of the UK, and forecasters say it will continue to be the major problem into the weekend.
Rain, sleet or snow will hit most areas and freeze in the sub-zero temperatures. In some places, daytime temperatures have plunged to -8C.
Rain, sleet or snow will hit most areas and become icy in the sub-zero temperatures. In some places, daytime temperatures have plunged to -8C.
The weather has continued to cause disruption, with some train services cancelled and many flights delayed.
The weather has continued to cause disruption, with some train services cancelled and many flights delayed.
Two pensioners have been found dead in their gardens in Cumbria this week.
Two pensioners have been found dead in their gardens in Cumbria this week.
Officers said it appeared 80-year-old Lillian Jenkinson, who was found dead in Workington on Wednesday morning, might have fallen in her garden in freezing conditions.
This weekend's sporting schedule, from football to horse racing, has fallen foul of the severe weather.
On Tuesday, an elderly man was found dead in his garden in Kirkby Stephen, and police - who are urging people to look out for each other in the cold weather - are trying to work out whether a fall or a medical condition may have contributed to his death.
Scotland is worst hit, with all Premier League football off, and many Football League fixtures have been postponed in England.
Meanwhile, a 57-year-old man died after he was hit by a Land Rover Freelander which skidded on ice on the A6108 at Bellerby, North Yorkshire.
The victim had gone to help a driver whose car had crashed.
School closures
School closures
Snow showers have eased in many areas but the Met Office has issued a severe weather warning for heavy snow for Cumbria and parts of south and mid-Wales. Between 5-10cm (2-4in) of snow are likely over the hills.
Snow showers have eased in many areas but the Met Office has issued a severe weather warning for heavy snow for Cumbria and parts of south and mid-Wales. Between 5-10cm (2-4in) of snow is likely over the hills.
Gatwick Airport has reopened but delays remain. Southern and Southeastern rail have reduced services, trains in East Yorkshire are cancelled, and there are virtually no services north of Glasgow.
Widespread ice warnings have been issued for the Highlands and western Scotland, Northern Ireland, Wales, north-west England, the Midlands, eastern England, the South West, London and the South East.
Gatwick Airport has reopened after being shut for two days but delays continue, and passengers are being told to check with their airline before leaving home. The Gatwick Express train is suspended but there are other rail options.
Several rail services in England and Scotland are either cancelled or severely disrupted, and drivers are again warned of icy roads.
Southern and Southeastern rail have reduced services, trains in East Yorkshire are cancelled, and there are virtually no services north of Glasgow.
Snow showers in many areas have eased but the href="http://www.metoffice.gov.uk/weather/uk/uk_forecast_warnings.html" >Met Office is now warning of heavy snow in some areas. The warnings for Scotland apply to Strathclyde and Central, Tayside and Fife, while there are icy road warnings for Orkney and Shetland, the Highlands, and the South West, Lothian and Borders.
href="/news/uk-scotland-11857919" title="At a glance: School closures in Scotland" >Many schools were closed again in Scotland - including all schools in Fife, East Lothian, Midlothian, West Lothian, North Lanarkshire and the Borders - and more than 2,000 are closed in England.
In England, as well as heavy snow forecast for the North West, there are warning of widespread icy roads across whole swathes of the country including the Midlands, the east of England, London and the South East, and the South West. There are similar warnings for Northern Ireland, and heavy snow and ice in Wales.
Overnight, temperatures fell as low as -20C in Braemar, -10C at Manchester airport and -10 in Yeovil.
The thermometer at RAF Leeming in North Yorkshire was showing -17.9C on Friday morning, making it the coldest night recorded at the station since records began in 1945. The daytime temperature at Leeming was -8C.
Both Manchester airport and Yeovil recorded -10C. The thermometer at RAF Leeming in North Yorkshire was showing -17.9C on Friday morning, making it the coldest night recorded at the station since records began in 1945. The daytime temperature at Leeming was -8C.
Areas such as Northern Ireland, western Scotland and north-west England are set to be the next affected by snow during the course of Friday. Drivers in Wales have been warned about icy roads and freezing fog, with outbreaks of snow and sleet in all areas.
In East Yorkshire and North Lincolnshire, heavy snowfall and icy conditions are causing problems on the roads and on public transport. At Brough, 23cm (9in) of snow fell overnight, blocking many roads.
The AA said it expected to attend more than 18,000 breakdowns on Friday - up from about 16,000 on Thursday. A typical Friday, normally the organisation's quietest day, brings about 9,500 call-outs.
The Independent Petrol Retailers Association claimed that up to 500 independent petrol retailers in Scotland and the east of England risked running out of petrol and diesel by the weekend. Filling stations in rural areas away from the main trunk roads were particularly vulnerable, it added.
A spokesman said: "It's busy all over the country due to the freezing conditions but the Glasgow area, Leeds and north-east England are particular hotspots."
The easing of snow showers meant Gatwick Airport reopened on Friday morning, although major delays and cancellations were expected to continue to cause headaches for travellers. Smaller regional airports were closed on Friday morning, including Robin Hood Airport in Doncaster, which is now closed until Sunday.
Transport Secretary Philip Hammond chaired an hour-long meeting on Friday morning to discuss the cold spell. Several government departments were represented, as was the Scottish Government, the Met Office, and Local Government Association.
A statement on Gatwick's website said: "Our advice to passengers remains - do not travel to the airport without first checking with your airline to make sure that your flight is departing today.
Our political correspondent Iain Watson said it was agreed that while the strategic road network was largely open and there were no major problems with health, gas supplies, or food and petrol distribution, there were some "local issues".
"Passengers should expect delays and cancellations and it is likely to take a few days before flight schedules return to normal. Train services to and from the airport continue to be limited and road networks are likely to remain severely affected by the weather."
The amount of grit was discussed and it was decided the UK was in a "better position than last year", when supplies ran out in some areas.
There are 1.2 million tonnes of salt held by local councils in England, a national reserve of 250,000 tonnes and more salt has been ordered. England's Highway Agency has 260,000 tonnes of salt compared with 227,000 this time last year.
No decision was taken as to whether rail firms should be fined for making widespread cancellations.
In other developments:
In other developments:
Southern trains, which operates in south London, along the south coast and between central London and the south coast, said it would be operating a revised timetable on Friday - with half-hourly services in most cases.
Southeastern trains, which runs out of London Victoria and Charing Cross into Kent and the south-east, said it was operating an extremely limited number of services from an emergency timetable
would be significantly reduced, with cancellations and delays, until Sunday
No trains are running between Cleethorpes and Doncaster, Lincoln and Grimsby and between Lincoln and Doncaster. The line from Bridlington to Scarborough is still blocked.
More than 800 schools are closed across Hampshire, Dorset and the Isle of Wight, more than 300 in East Yorkshire and North Lincolnshire, more than 500 in Essex, around 500 in Kent, more than 200 in Surrey, and more than 250 across Northumberland, Tyne and Wear and County Durham. In Derbyshire more than 230 schools remained shut, and more than 300 in Nottinghamshire.
Southern trains, which operates in south London, along the south coast and between central London and the south coast, said it would be operating a revised timetable on Friday - with half-hourly services in most cases.
Southeastern trains, which runs out of London Victoria and Charing Cross into Kent and the south-east, said it was operating an extremely limited number of services from an emergency timetable
and said its timetable would be significantly reduced, with cancellations and delays, until Sunday
No trains are running between Cleethorpes and Doncaster, Lincoln and Grimsby and between Lincoln and Doncaster. The line from Bridlington to Scarborough is still blocked.
More than 800 schools are closed across Hampshire, Dorset and the Isle of Wight, more than 300 in East Yorkshire and North Lincolnshire, more than 500 in Essex, around 500 in Kent, more than 200 in Surrey, and more than 250 across Northumberland, Tyne and Wear and County Durham. In Derbyshire more than 230 schools remained shut, and more than 300 in Nottinghamshire.
Transport Secretary Philip Hammond told the BBC the travel problems were not caused by a lack of grit.
Police in Cumbria are investigating the deaths of two elderly people, who died in their gardens in freezing conditions in separate incidents.
He said there were a million tonnes of salt in local authority depots, a further quarter of a million tonnes in Highways Agency depots, and about 150,000 tonnes on their way to the UK over the next five or six weeks.
Officers said it appeared 80-year-old Lillian Jenkinson, who was found dead in Workington on Wednesday morning, might have fallen in her garden in freezing conditions.
"We have massive supplies of salt, there is no shortage of salt. If local authorities are not gritting minor roads, residential roads, pavements, that is because they've taken a decision not to grit those roads and pavements.
On Tuesday, an elderly man was found dead in his garden in Kirkby Stephen, and police - who are urging people to look out for each other in the cold weather - are trying to work out whether a fall or a medical condition may have contributed to his death.
"No local authority has contacted us, and asked us for access to the strategic stockpile, and if they do, we have supplies ready to make available to them."
On Thursday night, a 57-year-old man died after he was hit by a Land Rover Freelander which skidded on ice on the A6108 at Bellerby, North Yorkshire. The victim had gone to help a driver whose car had crashed.
On Thursday Mr Hammond told the Commons he was doing everything he could to keep Britain moving, but his Labour shadow Maria Eagle accused him of "complacency".
The government said that "challenging" road conditions were making it difficult to supply fuel to some areas - even though the refineries themselves were operating without major disruption.
Mr Hammond said he had heard "far too many stories" of rail passengers being unable to obtain information about train services.
The transport secretary has written to the train companies to remind them of their responsibilities, but he has played down suggestions that the firms could be punished with fines for their performance during the cold spell.
Anthony Smith, chief executive of rail customer watchdog Passenger Focus, said some passengers had been "badly let down" by the rail industry's handling of the severe weather disruption.
But he added: "Fining train companies would only take money out of the railway pot to passengers' detriment."
An active search by mountain rescue team volunteers for missing fell walker Gwenda Merriot, 60, from Wiltshire, has ended, but posters are being put up and hotels and B&Bs are being contacted.
An active search by mountain rescue team volunteers for missing fell walker Gwenda Merriot, 60, from Wiltshire, has ended, but posters are being put up and hotels and B&Bs are being contacted.
She was last seen in Ambleside in the Lake District on Wednesday morning and there has been heavy snowfall since then.
She was last seen in Ambleside in the Lake District on Wednesday morning and there has been heavy snowfall since then.
Have you noticed any problems arising from the cold weather? Has your business been affected? Send us your pictures and comments using the form below.
Have you noticed any problems arising from the cold weather? Has your business been affected? Send us your pictures and comments using the form below.
Send your pictures and videos to yourpics@bbc.co.uk or text them to 61124 (UK) or +44 7725 100 100 (International). If you have a large file you canupload here.
Send your pictures and videos to yourpics@bbc.co.uk or text them to 61124 (UK) or +44 7725 100 100 (International). If you have a large file you canupload here.
