Fog grounds flights in Belfast and across the UK - and stops Eamonn Holmes from getting to Sky News studio
Heavy fog has disrupted flights across the UK, with 10% of departures cancelled from Heathrow Airport.
The yellow weather warning for fog covers much of England and east Wales.
EasyJet flights from Belfast International Airport and Gatwick were cancelled or delayed.
Early flights to Manchester, London City, Heathrow and the Isle of Man airports were cancelled from Belfast City Airport.
Sky News presenter Eamonn Holmes was caught up the travel chaos last night when his flight from Belfast to Heathrow was cancelled, meaning he did not make his morning television slot.
He tweeted: "Cancelled on British Airways then Flybe. Everything else full. Not getting out of Belfast. Ah well there are worse things in life."
The Met Office warned heavy fog could remain across the south of England until about noon.
Passengers are being advised to check the status of their flight with the airline before travelling to the airport.
After long delays on Sunday some travellers landed at Heathrow in the early hours of the morning, but many hoping to take off today will be disappointed.
A spokeswoman for the airport said: "We've got extra passenger ambassadors in the terminals to provide assistance for those travelling today.
Fog problems. Second attempt at landing for a Belfast - Manchester flight this morning. Video by Andrea Moor. pic.twitter.com/g3lzsvZ3Gh— Barra Best (@barrabest) November 2, 2015
"Once again we would like to apologise for the disruption."
Some passengers told of their relief on reaching London after delays caused by fog on Sunday, which also saw around 50 flights cancelled at Heathrow.
Jennifer Johnston wrote: " Safely landed at Heathrow. British Airways I forgive you for our 5 hr delay. The fog is real and thick!! "
Tom wrote: "A 2 hour delay but would like to thank British Airways for getting us back into Heathrow safely tonight despite the dense, lingering fog."
The Met Office weather warning is valid until midday, with fog expected to slowly clear throughout the morning.
The forecaster said the fog would become widespread and dense overnight into today and warned: " Travel may be impacted by poor visibility, with some minor disruption expected."
Visibility could be reduced to less than 100 yards, the forecaster added.
Motorists have been advised to take care on the roads amid the thick fog.
Highways England urged people to allow extra time.
The agency said on its website: "Road users will need plenty of extra time to do their usual commute, especially as the fog is expected to lift very slowly during the morning."
West Midlands Ambulance Service tweeted: "Weather update. It's very foggy!!! Drive slowly, use fog lights or better yet stay inside."
Flights continued to be disrupted at both Manchester Airport and Liverpool John Lennon Airport, with several services cancelled to and from Amsterdam, the Isle of Man, Southampton and Edinburgh.
The Liverpool airport tweeted: "Like the rest of the UK we are experiencing some delays & cancellations. Fog may affect your travel this morning so check for updates directly with your airline before your travel."