Heathrow
The fog lifted slightly in the afternoonGetty

Several airlines operating in Heathrow airport were forced to cancel their flights due to thick fog hanging low in the air. Some 50 trips were cancelled in total, causing major delays for passengers and costs for the airlines.

The intense fog has caused weather forecasters to issue warnings for drivers. The weather blocked views from just meters away. Londoners caught snaps from non-cancelled planes and other views in the capital, with the fog covering much of the city.

"All the fog has now been lifted," a spokeswoman told IBTimes UK. "Most of it was just this morning, so all the cancelled flights were scheduled in the morning. All flights are now back on schedule."