An eerie, dense fog has sparked travel chaos across the UK Tuesday.
Dozens of flights have been cancelled at Heathrow after thick fog engulfed the west London airport.
Fog also caused flight disruption at Cardiff airport.
By 10am a total of 85 flights at Heathrow had had to be axed and there were delays to a number of other departures and arrivals.
Heathrow staff advised passengers to check with their airline on their flight's status.
With the fog taking time to clear in west London, further flight disruption was expected during the last part of the morning.
At Cardiff, a number of flights were delayed and some were diverted to other airports.
The Met Office which gave a yellow "be aware" warning said patchy dense fog reduced visibility to 50 metres in parts of mid, south and west Wales.