Thousands of passengers are facing disruption as dense fog is tonight forcing the cancellation of flights in and out of London .
BBC NewsDense fog is set to spread overnight according to the UK Met Office, which has issued a series of severe weather warnings of worsening conditions.
Heathrow Airport and London City Airport in the Docklands have been affected throughout the day and Gatwick Airport has tonight been experiencing delays to both arrivals and departures.
Heathrow Airport said 132 flights, including 50 British Airways flights, have been cancelled due to heavy fog.
London City Airport suspended around 45 flights and delayed or diverted others due to "low visibility" this afternoon.
A Met Office severe weather warning issued tonight stated: “The public should be aware that areas of dense fog are likely to become more extensive across parts of London, southeast and eastern England this evening.”
The warning is valid until 10am on Monday morning.
A statement from Heathrow Airport said: "We are aware of 74 departing flights that have been cancelled by airlines. Some delays to flights are also occurring so we advise passengers to check with their airlines before travelling."
A total of 58 incoming flights were cancelled.
Heathrow warned disruptions could continue late into the night. Some airlines were re-booking passengers on other flights, while others are arranging for accommodation.
Some domestic passengers are being taken to their destinations by coaches, the airport said.
Heathrow Airport is open, but air traffic controllers have slowed the rate at which aircraft can land.
Drivers are warned that conditions are likely to be "difficult" and motorists have been advised to take extra care.
A weather warning for dense fog has also been issued for Yorkshire and Humberside, the East and West Midlands, the East of England and the South East.
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