Flights and trains have been cancelled and thousands of schools shut as sub-zero conditions continue across the UK.
Rail networks including Southeastern, South Western and ScotRail have advised people not to travel on their routes.
More than 13,000 customers are without power in the south west of England, south Wales and the Midlands.
The Met Office’s red warning has been lifted but flood warnings remain in place in the south-west and north-east of England.
South Western Railway’s last service from London Waterloo will be at 21:42 GMT on Friday.
Meanwhile, the RAC says that freezing rain could pose the biggest threat to drivers as black ice forms on roads.
Southeastern Railway has called in help from the police and fire service after frustrated passengers on four trains in Lewisham, south London left the carriages and started walking down the tracks.
Major incidents have been declared in Wiltshire, Hampshire and Avon and Somerset, as blizzards brought roads to a standstill.
The M62 near Manchester is closed “indefinitely” while the military helps police free stranded motorists. and 100 cars are currently stuck on the A505 between Hitchin and Luton says Hertforshire Police.
The body of a woman has been found during a search for the missing hillwalker, Alison Fox who went walking in the Ochil Hills behind Menstrie on Thursday afternoon.
A spokesman for the police has said “No formal identification has taken place at this time, however Alison’s family are being informed.”
There are yellow weather warnings for snow, ice and wind in place across the UK throughout Friday and Saturday, with a Scottish warning in force until 23:55 GMT on Monday, but there are no amber alerts currently in place.
Prime Minister Theresa May has thanked everyone “going the extra mile”.
In Scotland the armed forces are transporting vital NHS staff to the hospitals where they work.
Electricity North West says it has restored power to 20,000 homes in the north west of England but some rural areas could be without power overnight on Friday.
The Environment Agency has issued 15 flood warnings and 36 flood alerts for coastal areas in the south-west and north-east of England.
Severe flooding has been reported in Penzance, Cornwall, due to high river levels and swollen seas.
The Met Office said the UK has officially broken its record for the lowest temperatures for March in a 24-hour period.
Temperatures in the town of Tredegar in south Wales did not get above -5.2C.
Police forces across the UK have told people to travel only if necessary.
There is a warning of black ice on the M6, while some of the worst problems are near Rochdale on the M62 – which is closed as stranded vehicles are cleared – and on the A303 near Ilminster and the A31 in the New Forest.
On the M62, volunteers from Milnrow, Rochdale, took hot drinks, food and blankets to some of those stuck – including a bottle of warm milk for a five-week-old baby.
Responding to a call for help on social media, farmers used their tractor to drive off-duty midwives to a woman who had gone into labour in the remote village of Balgedie, near Kinross which had been cut off by the snow.
In Cumbria, a farmer has run out of feed for his 4,000 hens near Penrith and asked for a route to be cleared.
Commuters ‘almost jubilant’
By BBC transport correspondent Victoria Fritz
The more normal response to this level of travel disruption would be exasperation and even anger amongst marooned passengers.
But after a week of widespread chaos, the mood in Waterloo station on Friday at rush hour is almost jubilant.
The weekend is around the corner and many of the thousands here will be granted a temporary reprieve from doing daily battle with the railways.
The biggest gripe amongst passengers is that there has been precious little information of last minute changes to schedules.
Most are understanding of the extraordinary challenges track and train operators are facing.
Station staff are out in force and briefing passengers when they can. With the weather rapidly closing in, it’s a dash for all to get home before the clock strikes 22:00 GMT.
In Yorkshire up to 1,000 schools remain shut as more snow and strong winds are expected.
The Premier League has said games are expected to go ahead despite the weather, however four matches in the Championship and two games in the Scottish Premiership have been cancelled.
What is happening with the trains?
Across the UK, more than 20 rail operators are running a reduced service.
National Rail is advising passengers to check their service before travelling. Some train operators are urging people not to travel at all.
- Virgin Trains is not running any services north of Newcastle on Friday, with their route between Carlisle and Scotland – affecting the London to Glasgow and London to Edinburgh routes – closed with no replacement buses running. Passengers on east coast routes are urged not to travel until Saturday
- Arriva Trains Wales has said that most trains are not running and passengers have been advised not to travel all day on Friday. There are limited trains between Shrewsbury and Crewe, Crewe and Chester, Chester and Holyhead, Wrexham and Bidston and Swansea and Carmarthen
- Great Western Railway said it was running an “extremely limited service” and advised against travel
- Heathrow Express services between London Paddington and Heathrow Airport are running three times an hour
- East Midlands Trains are running a reduced timetable with no trains between Lincoln Central and Grimsby Town, and between Sleaford and Skegness
- There are numerous delays and cancellations on the Northern network
- ScotRail has suspended most routes and advised customers not to travel. There are limited services, including between Glasgow and Edinburgh
- CrossCountry is not currently operating services between Bristol and Plymouth, Bristol and Birmingham, Birmingham and Cardiff, and between Newcastle and Scotland
How are the airports affected?
More than 1,250 flights have been cancelled across the UK and Ireland on Friday.
- Glasgow Airport: Open after “the worst snowfall in its history” but there are delays and cancellations
- Edinburgh Airport: Open with numerous delays and cancellations. All EasyJet and Ryanair flights are cancelled
- Dublin Airport: All flights have been suspended until Saturday
- Cardiff Airport: The airport will be closed until Saturday morning
- Bristol Airport: Runways are now open but there are significant disruptions. EasyJet has cancelled all flights to and from the airport
- East Midlands Airport: It has warned passengers of cancellations and delays
- Leeds Bradford: The airport has opened but is experiencing delays
- Heathrow Airport: The airport advises passengers to check before travelling
- Gatwick Airport: There are delays and cancellations
- City Airport: The runway is currently closed while staff clear the snow
- Birmingham Airport: Runway unlikely to reopen before 22:00 GMT on Friday
What is the forecast?
The Met Office says the cold weather could last into next week and possibly the following week.
Up to 50cm (19 inches) of snow is forecast in parts of Dartmoor, Exmoor and uplands parts of south-east Wales accompanied by gales or severe gales in exposed areas.
Gusts of 60-70mph are possible in parts of northern England and Wales.
Up to 10cm (four inches) of snow is forecast in parts of Scotland and northern England, with up to 25cm over the area’s hills.
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