Heavy fog blanketed the Portsmouth area today.
Drivers were warned to take extra care on the roads as visibility was drastically reduced.
There were reports of a crash blocking one lane of the M3 southbound between junctions 11 and 12 near Eastleigh, but managers at the Romanse traffic centre said no other major incidents had been reported.
Hovertravel, which had planned to resume to a full timetable today after maintenance issues last week, said the weather conditions were disrupting services on the Southsea-Ryde route.
And some flights from Southampton airport, as well as from Gatwick and Heathrow, were grounded.
A Southampton airport spokesman said: ‘We are experiencing delays and cancellations due to poor weather in Southampton and in some of our destinations. For more up to date information please contact your airline.’
Around 45 flights, 10% of departures from Heathrow airport, have been “pre-cancelled” as a yellow weather warning for fog covers much of England and east Wales.
After long delays on Sunday some passengers landed at Britain’s busiest airport in the early hours of the morning, but many hoping to take off today will be disappointed.
A spokeswoman for Heathrow airport said: “We’ve got extra passenger ambassadors in the terminals to provide assistance for those travelling today.
“Once again we would like to apologise for the disruption.”
Passengers are advised to check with their airline for updates.
Those hoping to travel through Gatwick have also been advised to check ahead for any disruption.
Some passengers told of their relief on reaching London after delays on Sunday, which also saw around 50 flights cancelled at Heathrow.
Jennifer Johnston: “ 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 BritishAirways 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, it added.
Motorists have been advised to take care on the roads amid the thick fog.
Jack Lewis of West Midlands Ambulance Service tweeted: “Weather update. It’s very foggy!!! Drive slowly, use fog lights or better yet stay inside.”
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.”
Sky News presenter Eamonn Holmes was one of those stranded by the fog.
He was u nable to make it to London in time for the Sunrise television news programme at 6am.
He tweeted on Sunday: “Not getting out of Belfast” after flights were cancelled and added that he had been unable to join his colleague on the show.
“ How’s TheFog in Old London Town this Morning? Tell skysarahjane cos The Pea Souper stopped me being able to join her. No Flights,” he wrote on Monday.
Early flights to Manchester, London City and Heathrow airports have been cancelled from Belfast City Airport.
British Airways said the fog was affecting flights at Heathrow, Gatwick and London City Airports and advised passengers to check online for updates.
*Our picture shows fog on Portsdown Hill this morning.