Almost one million people from Northern Ireland used Dublin Airport in the first nine months of the year.
Dublin Airport Authority (DAA) confirmed yesterday that it had broken the 30 million passenger milestone in 2018 for the first time in its history with 12 days of trading left.
DAA told the Business Telegraph: "About 965,000 Northern Ireland residents used Dublin Airport in the first nine months of this year, which was a 4% increase on the same period in 2017."
When inbound visitors using Dublin Airport to travel across the border are factored in, the number for the whole of 2018 is expected to exceed two million.
Belfast International Airport, meanwhile, has experienced a difficult year dogged by complaints of long queues in its security area and frustrating delays in baggage.
Wilson James took over the airport's security services on November 1, promising to recruit 50 new staff in a bid to tackle the problem.
Belfast International Airport also lost its only transatlantic route in October when Norwegian Air pulled the plug on its New York flights, citing a lack of demand.
The move prompted a scathing statement from the airport, labelling Norwegian's offering as "inferior", accusing the airline of "moronically channelling much greater levels of Northern Ireland passengers onto Dublin flights".
DAA, which is led by Dalton Philips, said yesterday that its transatlantic traffic rose to 3.8m this year, representing an increase of 16% on last year.
The number of people using the airport for connecting flights between Europe and North America also shot up by 18% to 1.7m in the year to date.
The airport said that the 30m milestone had followed 57 months of continuous growth in passenger numbers.
It's just three years since Dublin Airport passed the 25 million passenger threshold.
Since 2011 it has added 130 new routes, bringing on 30 new airlines.
The airport plans to add 18 more routes next year.
These will include new services to Toronto Hamilton, Halifax Nova Scotia, Dallas-Fort Worth, Calgary, Minneapolis-St Paul, Montreal and Kiev.
Meanwhile, easyJet has said it is preparing for a record-breaking Christmas, with more than 3.75m passengers expected to fly over the festive period of December 17 to January 4.
The airline expects the busiest day of the festive period to be on December 23, with more than 13,000 passengers set to fly from Belfast International Airport on 104 flights.
EasyJet UK country manager Ali Gayward said: "We're seeing high demand across our network on December 23 as more people than ever are flying either home or on holiday with us."