Flights at Northern Ireland's main airports were slowly returning to normal after disruption caused by bad weather in England.
Flights were cancelled due to fog
Heathrow airport has been worst affected, but there were also problems at other airports.
However, the managers of George Best Belfast City Airport and City of Derry Airport said backlogs were gradually being cleared.
Both airports said they expected to provide a full programmes of flights.
Earlier, British Airways announced the cancellation of all domestic flights from Heathrow Airport.
Mark Beattie, operations director at George Best Belfast City Airport, confirmed that the situation was "by and large, getting back to normal".
"Perhaps the most notable disruption remaining was to those routes in the south-east of England, most notably, Heathrow, but we are committed to a full programme for the rest of the day," he said.
"Typically, flights to Heathrow were incurring delays of up to two and three hours but more recently, that has been steadily improving.
"In fact, the most recent departure has come forward by an hour and that's good news for everyone."
John Devine, manager of City of Derry Airport said they had experienced a delay from London-Stansted "of up to 40 minutes".
He said, however, that flights to the Liverpool and the east Midlands would be "operating very much to schedule".
"Later on this evening the London flights possibly will incur some delay due to the fog at London and the air traffic control slots," he said.
He added that a full programme of flights was planned from Derry for the rest of the day.
On Wednesday night, many flights were cancelled due to fog.
Those flights that did make it through were severely delayed, which meant a long wait for passengers.
Many people trying to make it back to Belfast were stranded in England on Wednesday night.
The knock-on effect was a number of cancelled departures that left those travelling home from Belfast looking for somewhere to stay.
With the heavy fog expected to continue in parts of England further delays are expected.