Total passenger traffic figures for Aer Lingus rose by 2.1% to 1.1 million year-on-year in July.
The figures include the number of flown passengers on Aer Lingus Regional.
But the airline's mainline passenger numbers were down 0.7% to 1,004,000.
Short haul passenger numbers fell by 1% to 905,000 while long haul passenger numbers rose by 2% to 99,000 in July.
Aer Lingus Regional, which flies routes such as Cork to Bristol and Knock to Birmingham, showed a 40% increase in passenger numbers to 105,000.
The airline said its load factor last month increased by 2.1 points to 86.6%. Its short haul load factor rose by 2.4 points to 85.1%, while capacity decreasing by 1.9%. The long haul load factor increased by 1.5 points to 89.9% with no change in capacity.