Passengers flying to and from London airports have suffered flight delays due to fog on Friday morning.
Air traffic management firm Eurocontrol said poor visibility affected Heathrow, Gatwick, Stansted and London City.
The conditions meant a number of planes were delayed.
The UK’s busiest airport, Heathrow, had 41 departures delayed by at least 15 minutes between 6am and 9am.
A total of 35 departures at Gatwick were delayed over the same period.
Fog causes flight disruption as it forces air traffic controllers to make more use of radar rather than physically looking at the aircraft they are guiding.
This means the spacing between planes has to be increased, reducing the rate at which flights can take off and arrive.
Other European airports affected by fog include Brussels, Amsterdam, Paris Charles de Gaulle and Venice.
The Met Office issued a yellow weather warning for fog in parts of England and warned of possible delays to road and rail journeys during the morning rush hour.
The warning covers parts of the East Midlands, Suffolk, south-east and south-west.
The fog will slowly clear and Friday is set to bring mild temperatures for many, with highs of 13C (55F) in London, 15C (59F) in Leeds, 14C (57F) in Edinburgh and 16C (60F) in Aberystwyth.
Thursday was the warmest February day in Scotland, as Aboyne in Aberdeenshire hit a maximum temperature of 18.3C (64.94F) in the afternoon.
It beats the previous high of 17.9C (64.22F) recorded in Aberdeen on February 22 1897.