Aer Lingus says its total passenger numbers grew by 10.8% last month to 706,000 from 637,000 the same time last year.
The airline's short-haul passenger numbers rose by 10.2% to 625,000, while its long-haul numbers increased by 15.7% to 81,000.
Its load factor, however, fell from 69.2% to 64%, as the airline increased capacity on both its short-haul and long haul routes. Its short-haul load factor slipped slightly to 66.1% from 66.9%. The load factor on its long-haul routes slipped 11 points to 61.4% from 72.5% as the airline increased capacity by 42% with the introduction of two new long-haul aircraft.
Aer Lingus started its new controversial Belfast-Heathrow service last month and it said load factors for the service were encouraging and ahead of expectations.
It said it will start further services from Belfast later this month with the deployment of a third plane at the airport.
