The Dublin Airport Authority (DAA) has predicted that the group's passenger traffic may fall by up to 1.5 million to 19 million this year due to the depressed economic environment affecting air travel.
The projection has been made by DAA chief executive Declan Collier who said there will be a 20% decline compared with the 23.5 million recorded in 2008.
Dublin Airport's passenger numbers, which account for 65% of all passenger air traffic in the nation, dropped by 14% in the first quarter of 2010 compared with the same period in 2009.
Furthermore, the closure of European airspace this month led to the DAA cancelling 3,200 flights in and out of its airports, affecting about 400,000 incoming and outgoing passengers.
The DAA said it will carry out trial flights at Dublin Airport's new Terminal 2 in preparation for its opening in November this year.