Perth Airport is Australia's most punctual capital city airport for both arrivals and departures, according to Airline On Time Performance figures for May.

The figures, released by the Bureau of Infrastructure, Transport and Regional Economics, show that 89.5 per cent of all flights that departed from Perth were on time, ranking it first against other Australian capital cities for the month of May.

It also ranked first for arrivals with 88.8 per cent of all flights arriving on time.