EasyJet was forced to cancel 173 flights in May, mainly due to French air traffic control strikes and weather conditions.
The budget carrier still managed to improve year-on-year carryings by 5.7% in the month to 6.8 million.
However, the load factor edged down from 91.6% to 91.5%.
The May figures saw the airline’s annual rolling total of passenger carryings rise by 7.3% to almost 71.5 million.
Increased long haul demand helped lift passenger numbers by 11% last month at Norwegian, Europe’s third largest budget airline.
Carryings were up to more than 2.6 million passengers over the same month last year.
The load factor improved by 3.4 percentage points to 88.3%.
Norwegian chief executive, Bjørn Kjos, said: “We are very satisfied that an increasing number of business and leisure passengers are choosing Norwegian.
“On intercontinental routes in particular, we are experiencing increasingly strong demand as we continue to launch new routes and destinations, not least between London Gatwick and the US.”
The airline took delivery of one Boeing 737-800 in May as part of plans to introduce 21 aircraft this year.