"The situation has improved significantly since the last two days, " she said. "London Heathrow suffered pretty badly, but things are getting back to normal and the situation is easing - albeit slowly."

There was chaos earlier in the week when flights out of London and other UK airports had to be cancelled due to heavy fog.

Yesterday, passengers were advised to arrive on time for their flights and to be aware that there might be slight delays in getting them to their destination.

Meanwhile, Aer Arann put on 10 extra flights yesterday in order to get their passengers home in time for Christmas.

"We have put on extra seats so that nobody is left stranded, " a spokesman said. "Ten extra flights were put on out of the UK, in addition to our normal schedule, and these are all operating on or close to time."

Met ةireann has forecast that the weather should remain clear and dry over the weekend and further delays are not expected. "It's hard to predict what will happen in airports abroad, over which we have no jurisdiction, " said the Aer Rianta spokeswoman. "But, all going to plan, we are expecting no further trouble this Christmas."