Flight schedules have been scaled back today and tomorrow at London Heathrow due to extreme wintry conditions across the UK and Europe.
The airport said it has worked with airlines to consolidate today’s flying programme to ‘provide more certainty around departing flights, and ensure the safety of our passengers and colleagues’.
Gatwick Airport also warned that many flights today are cancelled or will be delayed.
Passengers are advised to check with their airline and not to travel to the airport if their flight is cancelled.
Those flying have been told to allow extra time for their journey.
British Airways said the ‘very poor’ weather conditions will continue to affect some of its flights.
"We recognise the uncertainty that the bad weather may be causing customers and have therefore introduced a range of flexible rebooking options for customers flying to or from London Heathrow, London Gatwick or London City airports," it said.
Passengers due to travel on any short haul service up to and including Sunday March 4, regardless of whether their flight is currently showing as operating or not, can rebook to a later date and travel on dates up to and including Wednesday March 21.
The same policy applies to anyone due to travel on a long haul service to or from London Heathrow.
Meanwhile, easyJet warned of disruption to many flights.
It has cancelled all flights to and from Edinburgh and Glasgow for the rest of the day.
"We are also seeing many cancelled flights across other airports including Bristol and Geneva," it said.
"We strongly advise all passengers due to travel today continue to check their flight status by using Flight Tracker and avoid travelling to the airport if your flight is cancelled."
Ryanair said all flights to and from East Midlands, Leeds Bradford, Edinburgh, Glasgow, Cork and Kerry Airports have been cancelled for the remainder of the day, plus some from Dublin.
It expects further flight delays and cancellations on Friday.
