Thick fog moving across the UK is threatening to cause travel mayhem, with airports warning of cancellations and flight delays.
The Met Office issued a severe weather warning lasting into Sunday afternoon, saying reduced visibility would continue to affect southern England and south Wales and creep into the Midlands.
Heathrow Airport warned "heavy fog" was delaying and cancelling flights and told passengers to check status updates with airlines before heading to their terminals.
Gatwick Airport apologised for Saturday's disruption and warned of further delays to both arrivals and departures as visibility was expected to be as low as 50 metres.
Met Office meteorologist Luke Miall warned drivers to take care in the persistent fog and told Christmas shoppers to give themselves extra time.
"There's no wind to help move it across, that's why it's persisting for quite some time," he added.
"The fog was there throughout yesterday as well but it has become more widespread throughout the night.
"But I think as we go through the day we will see the fog start to move out."