Snow and icy conditions have continued to cause travel chaos, with 175 flights cancelled at the UK's busiest airport and many train services struggling to cope.
At Heathrow, some 10% of flights were expected to be cancelled, and the situation was expected to get worse after 4pm when visibility is due to be low. Passengers are advised to check the status of their flights before travelling to Heathrow.
On Sunday, people were left fuming after 260 flights were cancelled - 20% of the airport's usual business.
A Heathrow spokesman said: "Many airports have plenty of spare runway capacity so aircraft can be spaced out more during low visibility without causing delays and cancellations. Because Heathrow operates at almost full capacity, there is simply no room to reschedule the delayed flights."
Other airports including Gatwick and Birmingham also experienced disruption to flights because of the wintry conditions, while Robin Hood Airport near Doncaster, South Yorkshire, was closed, along with the runway at East Midlands Airport.
Thousands of children had an extra day off as hundreds of schools remained closed. In some cases, parents were asked to bring shovels to help clear paths to enable them to open. A layer of snow and icy conditions also proved hazardous for motorists in the Monday morning rush hour.
Heavy snowfall closed two major roads across the Pennines, the A628 Woodhead Pass and the A66 between Brough and Bowes. The Highways Agency said both routes would be closed for some hours and advised drivers to find alternative routes across the Pennines.
One person was killed in Essex in an accident on the A12 in Essex, and drivers were being warned to take extra care. A teenager was left fighting for his life after suffering head injuries in a sledging accident in Middlesbrough and a man was taken to hospital in Kent with broken bones in his face when he was racially attacked after confronting a group of youngsters throwing snowballs at him.
Eurostar, Virgin Trains, First Capital Connect, Southeastern, Southern and South West Trains were all facing disruption. There were delays on some London Underground lines, mainly because of late finishes to engineering work, while the bad weather caused hold-ups on the London Overground service.
A woman, believed to be in her 20s, died after being found collapsed in the snow. She was discovered by a man walking his dog in Church Meadow, Deal, Kent, at 7.30am on Sunday and pronounced dead at the scene.