Three hundred thousand people are expected to travel through Dublin Airport this bank holiday weekend, with more than 2,000 flights arriving and departing.
The Dublin Airport Authority is advising passengers to be prepared before they set out for their flights.
It says extra staff will be on duty to deal with the higher passenger volumes.
Spokesperson Siobhan O'Donnell said: "Check the terminal you're departing from before leaving home. As a general rule, Aer Lingus, Aer Lingus Regional, Emirates, Etihad Airways, Delta Airlines, United and all the US flights operate from terminal 2, while other airlines operate from terminal 1.
"Passengers should plan to arrive in the terminal building at least 90 minutes before their departure time, irrespective of whether they're checking in at the airport."