The backlog of passengers at Heathrow Airport has almost been cleared with just a few dozen people still stranded.
BAA said services should now be returning to normal
Hotels which have accommodated hundreds of stranded passengers say most have now caught flights or returned home.
The dense fog which caused flights to be cancelled at Heathrow has lifted and planes are operating as normal.
Fog led to 86 flights being cancelled on Sunday and 60 more were cancelled on Monday because planes were in the wrong places, affecting 9,000 passengers.
The few dozen people left in hotels around Heathrow are mainly "transit passengers" who do not live nearby and are expecting to get away over the next couple of days.
Airport operator BAA said services should now be back to normal.
But it said all scheduled Christmas flights were now fully booked and that meant many of those originally booked onto cancelled services were now stuck.
The flights cancelled from Heathrow on Monday were due to depart from terminals one and four to destinations including Newcastle, Dublin, Glasgow, Edinburgh, Aberdeen, Paris, Brussels, Barcelona, Geneva and Berlin.
About 1,000 people had to spend the night at Heathrow following Sunday's cancellations.
At London City Airport, the website listed one cancellation to Edinburgh, with the five others to European destinations.
Gatwick Airport said six outgoing domestic and short-haul flights were cancelled, in addition to six incoming flights.
Stansted Airport reported being very busy, but with only minor delays.
Airports across other parts of the UK were also largely keeping flights on schedule.
Manchester Airport said two BA flights were cancelled due to the repercussions of cancellations around London.
Four flights were also cancelled from Edinburgh Airport for the same reasons - two destined for Heathrow, one for London City Airport and one for Birmingham.
Glasgow Airport had one flight cancelled in the morning, also to Heathrow.
Greg Ward, operations director for BAA at Heathrow, told BBC News people had been upset by the cancellations but understanding about the situation.
"In fairness a lot of people understand it's not got anything to do with the airlines or the airport," he said.
The forecast is for a wet Christmas Day in England and Wales with Wednesday a dry, bright and breezy day, but rain will move into Scotland and Northern Ireland.
On Thursday, rain over northern England and Wales will move slowly south.
Meanwhile, train companies have been criticised for not running services between Christmas Eve and Thursday. MPs have called it Europe's worst Christmas train service.
They say the companies should provide some services for the 25% of Britons without access to a car.
But train companies say they would need subsidies to meet the cost of Christmas trains.