The start of the summer holiday period helped Aer Lingus record a 4.3% rise in passenger carryings.
Total numbers rose to 1.26 million in July over 1.21 million in the same month last year.
The overall load factor increased by 1.3 percentage points to 88.6%.
Long-haul traffic was up by 18.3% in the month to 168,000 while short-haul numbers increased by 3.7% to 962,000.
But the Irish airline’s regional arm saw a 5.6% drop in passengers to 134,000.
Monthly carryings in July by Aer Lingus, which has recommended a takeover by British Airways parent International Airlines Group, compare with more than 10 million flown by budget Irish rival Ryanair and 7 million by easyJet.