As snow and ice loomed over London, airports across the capital have cancelled dozens of flights.
Heathrow and Gatwick airports both said some flights were cancelled in advance of the snow, which is set to begin at five o'clock tonight.
Meanwhile, Luton and City airports both said they will keep travellers up to date.
Heathrow said around 80 flights had been cancelled, while Gatwick said so far, four flights will not take off.
Good morning. Wintery weather is expected at the airport today and airlines will be adjusting their schedules as a result. 1/2— Heathrow Airport (@HeathrowAirport) January 12, 2017
Snow & poor weather may cause delays & cancellations to flights today. Please check the status of flights with your airline before travel.— Gatwick Airport LGW (@Gatwick_Airport) January 12, 2017
''The latest forecast is for snow this afternoon, which will reduce the number of aircraft able to take off and land each hour," said a Heathrow spokesperson.
"Alongside our airline partners and [air traffic service] Nats, we have taken the decision to reduce the flight schedule on Thursday, to allow airlines to rebook passengers onto un-allocated seats ahead of time where possible.
"We advise passengers to check their flight status with their airline before coming to the airport. We apologise to those whose travel has been affected."