Heathrow and London City Airport flights disrupted by fog
Heathrow Airport has cancelled 40 flights and several other planes were delayed because of poor visibility due to fog.
A spokeswoman for the west London airport said cancellations had mostly affected short-haul flights.
The widespread fog and mist also led to delays and cancellations at London City Airport.
A normal service has resumed at both airports but there are still some delays due to the earlier disruption.
However, service on the Woolwich ferry was not affected.