Air passengers today experienced a second day of disruption due to heavy fog in many parts of Britain.
Aer Lingus cancelled a number of flights between Dublin and some UK airports this morning.
The airline has also warned of further delays and cancellations due to the adverse weather conditions.
This evening the Dublin Airport Authority said there are delays of up to four hours across the flight schedule to the UK and some parts of Europe because of the fog.
Passengers are advised to consult with their airline or airline's website before arriving at the airport.
Flights to Manchester, London City and Heathrow airports have been cancelled from Belfast City Airport.
Meanwhile forecasters have warned that the thick fog is likely to return for a third day tomorrow.
Around 129 flights, 10% of departures from Heathrow Airport, were cancelled today due to air traffic restrictions caused by low visibility.
The UK Met Office issued a yellow weather warning for fog, covering much of England and east Wales until noon tomorrow.
Among those caught up in the delays at Dublin Airport is Rory O'Neill, also known as Panti Bliss.
He was due to fly to London this morning for a day of screenings and press interviews for his new documentary film 'Queen of Ireland'.
The head of external communications at Dublin Airport Authority said Dublin Airport is open and fully operational.
Siobhan O'Donnell said there is some fog at the airport but it is not as dense as yesterday evening.
She said six flights into the London area, which has been badly affected by fog, have been cancelled.
Speaking on RTÉ’s Morning Ireland, she said "low-visibility procedures" were in operation at Dublin Airport and advised passengers to continue to check with their airlines before coming to the airport.
"What we have on the airfield at Dublin Airport ... is called low-visibility procedures, which slows the operation down, which means that there will be knock on effects to the flight schedule.
Ms O'Donnell said: "The good news is that we're hearing that the fog will lift at around 9am this morning here at Dublin Airport.
"However, we don't know what is going to happen into the UK so delays may continue throughout the day."
Flights are also disrupted at both Manchester Airport and Liverpool John Lennon Airport, with several services cancelled to and from Amsterdam, the Isle of Man, Southampton and Edinburgh.
A spokesman for Manchester Airport said: "Like much of the UK, Manchester Airport has been affected by the fog and low visibility over the past couple of days.
"There have been periods where conditions have improved, flights have landed as normal and we have been able to accept diverted flights from other airports experiencing the same issues.
"However, it does look like the foggy conditions could remain throughout the morning, and we would ask customers to check with their airline about the status of their individual flight.
"Passenger safety remains our number one priority and we will work with our third parties on site to ensure all passengers are cared for during these conditions," the spokesman added.
