One hundred flights have been cancelled at Heathrow so far today amid reports that the hub airport is like a "refugee camp" due to weather-related disruption.
A spokeswoman said that although weather conditions have improved, about 100 flights have had to be cancelled in a "recovery" from yesterday - 67 of which are departures.
"In terms of how today is going so far, the weather conditions are much better today. The runways are open.
"We do have about 100 cancellations at the moment, but that's really just recovery from yesterday.
"Two-thirds of that 100 - 67 of the cancellations - are departures, and the remainder are arrival cancellations.
"At the moment the airport is operating as usual. We have the same number of aircraft using the runways as we normally would," the spokeswoman said.
Meanwhile, Simon Calder, travel editor of the Independent, painted a bleak picture when he told the BBC that Heathrow looked like "a refugee camp", with people sleeping on the floor.
Mr Calder said people were angry at the lack of information and the short notice of flights being cancelled.
He said people were stuck on planes "for many hours" last night as they waited to take off because the rate at which planes departed was dramatically cut.
There are delays of up to 20 hours on flights arriving from Europe, he added.
British Airways had to cancel "in the region of 30" flights today due to what it says is "knock-on disruption from yesterday".
A spokesman for BA said: "We have unfortunately had to make a number of cancellations today, mainly due to knock-on disruption from yesterday, so we've got a number of aircraft out of position and it's quite a complex operation to put that back together, so that's what we're working on at the moment."
Commenting on the number of flights affected, he added: "It's in the region of 30. Those are predominantly short-haul flights to domestic and European locations."
BA is now offering customers who no longer wish to travel this weekend the chance to rebook their flight for a later date.
It is also providing refunds and overnight accommodation to those who could not fly, or letters for them to make a claim at a later date.
Meanwhile, Gatwick Airport is operating as normal today, with no knock-on from yesterday's bad weather, a spokeswoman said.
No major cancellations are expected, and 505 flights are scheduled for the day.
"We are advising passengers to check their plans before they travel, and urge people who are travelling this weekend to be aware that there could be disruptions at airports across Europe or in other parts of the UK," said the spokeswoman.
Stansted Airport announced via its Twitter feed: "Overnight snow clearance means flights operating as normal this morning @STN--Airport. Passengers can check flight status on airline website."