Passengers numbers have soared at Dublin Airport, helped by new routes and extra frequencies. Last month, a record 2.3 million people passed through the airport, up 14% on the same month last year.
The surge is partly due to the Rugby World Cup, with both Ryanair and Aer Lingus laying on extra flights for fans travelling to matches in England and Wales. And between June and September, Dublin Airport handled a total of 10.1m passengers, up about 15% year-on-year.
Transatlantic traffic jumped 16% in September to nearly 275,000 passengers, and the airport is predicting further significant growth in North American traffic, with Aer Lingus expected to relaunch its route between Dublin and Los Angeles.
But the figures make grim reading for the management teams at Belfast International and George Best Belfast City Airports.
Although both terminals have enjoyed increased passenger numbers this summer, and are anticipating further growth, they're locked in a constant battle with Dublin Airport to retain passengers.
In May, Dublin Airport revealed that the number of Northern Ireland residents using the hub had increased by 52% to a record 864,000 last year. New York JFK is the most popular destination for local consumers using Dublin Airport, followed by London Heathrow, Manchester, Dubai and Rome.
The airport has been running advertising and marketing campaigns in Northern Ireland in recent months, which had helped grow business, according to spokesman Paul O'Kane.
"We have been advertising regularly on radio, outdoor and print media in Northern Ireland and this will continue. We've also been working closely with our airline partners to promote their specific products to consumers in Northern Ireland through mainstream advertising, marketing activity with the travel trade and a series of radio promotions."
One of the major factors in the growth of northern passengers is the Republic's move to scrap the departure tax - Air Passenger Duty - which still applies to flights from Northern Ireland airports. Despite vigorous campaigning by both airports and leading business groups, Stormont decided to retain the duty after an economic report estimated that abolishing it would have come at a cost of over £7m per year to the block grant.
Earlier this week, Belfast International Airport called on the Assembly and Executive ministers to take action to help the travel industry here.
Revealing a 12% growth in passenger numbers for September - and predicting further growth in the coming year - managing director Graham Keddie said: "There is immense untapped potential in this sector.
"More than anything else, these figures should serve as a call to action.
"We are determined to expand the route network and attract new airlines, but there has to be meaningful support and a long overdue acknowledgement that this is a sector that is capable of creating thousands of new jobs.
"Other countries have fully recognised the importance of the sector to their economies and it's time that we, too, did the same."