Persistent freezing fog has meant the cancellation of another 100 flights at Heathrow Airport for the second day on the trot.
The Met Office issued a yellow fog warning for the majority of southern England last night, advising people to be aware.
Today the fog reduced visibility at the airport, which warned passengers to expect disruption throughout the day.
Fog across London is expected to cause disruption to flights at Heathrow today. Please check with your airline prior to travelling. pic.twitter.com/kaTMbVnYSm— Heathrow Airport (@HeathrowAirport) January 24, 2017
It has advised passengers to check the status of their flights before setting out.
The airport has said that as it operates at near full capacity, there aren't gaps in its schedule that can be used for delayed flights.
We're expecting some delays this morning due to fog. Please check-in as usual and contact your airline for specific flight information.— Southampton Airport (@SOU_Airport) January 24, 2017
Southampton has also warned there might be delays.
Yesterday, Heathrow, along with London City, Gatwick and Southampton, all cancelled flights due to the lingering fog.
London City said visibility had improved, but with forecasts showing more fog later, passengers should keep an eye on airline information if travelling.
Gatwick said air traffic control restrictions imposed due to the heavy fog had caused delays on flights both to and from the airport yesterday, as well as causing some cancellations.
It's not the best week for weather havoc to add to confusion for passengers, as Gatwick has kicked off its airline merry-go-round too. British Airways, EasyJet and Virgin Atlantic are swapping terminals - EasyJet has moved to the North Terminal from today.
The airport has said extra staff will be on hand to help direct passengers.