In the wake of heavy snowfall and severe weather warnings, London's Heathrow Airport cancelled 30% of flights that were scheduled to take off on Sunday.
The world's busiest international passenger airport said that up to 10 centimetres of snow were expected to fall which would cause major disruption at the west London airport without reductions to the flight schedule.
Heathrow's chief operating officer Normand Boivin said, "We deeply regret any disruption caused to passengers by the cold weather." He promised to return the airport to normal as quickly as possible.
Road traffic was also disrupted since last evening as snow hit southern Scotland and parts of Wales before moving south-east through England.
Over 10,000 tonnes of salt were being spread on the capital's roads to facilitate movement.
The Stansted airport was closed temporarily to clear snow.
The British Airports Authority, which runs Heathrow, said one-third of today's approximate 1,200 flights would be cancelled. Since most flights to India leave at night, no cancellations about those were announced so far.
The decision to introduce a revised flight schedule was taken to minimise disruption to passengers, Boivin said.
Air passengers at London's Heathrow, Gatwick and Stansted airports have been advised to contact their airlines for more information.
Similar disruptions in air traffic have been reported across Europe.
Flights from Rome and Amsterdam's Schiphol airports to UK destinations, and last morning flights to Amsterdam from Birmingham, Manchester and Heathrow were cancelled or delayed.
The British Airways said it would allow passengers scheduled to fly today to re-book for journeys between Monday and Thursday.
In some parts of Europe, temperatures have fallen as low as -30C, and scores of people have died due to severe cold wave conditions, including more than 100 in Ukraine.