Airports including Heathrow and London City are reporting delays and cancellations due to freezing fog overnight.
Heathrow's Twitter page advised at around 09.00 this morning that "There are delays and cancellations to flights due to freezing fog. Check your flight status with your airline."
The airport's website also shows several delays, and the BBC has reported that around 80 flights have been cancelled this morning.
London City airport's Twitter page also advises that "Due to poor weather conditions this morning, flights are experiencing disruptions. Passengers should call their airlines."
The airport says it is "expecting the fog to clear from 11.00".
Gatwick and Stansted airports are currently reporting normal operations.
heathrowairport.com
londoncityairport.com