Auckland International Airport (ASX:AIA, NZE:AIA) expects June 27 to be the busiest day for international departures, with nearly 15,000 travellers set to fly out of the airport, according to a Wednesday statement.

International traveller numbers are set to reach over 680,000 from Wednesday to July 19, rising 1.5% on the same period in the previous year for departures and arrivals.

Meanwhile, domestic traveller numbers are expected to be slightly softer with around 570,000 travellers coming and going, down 3.5% year-over-year. Domestic travel is expected to be busiest on Mondays, Thursdays, Saturdays, and Sundays.

Transit passenger numbers are also growing, up 16% year over year.