London Luton Airport is the worst in the UK for delays, according to figures compiled by the Press Association.
Using data from the Civil Aviation Authority, the organisation found passengers at the airport could expect an average delay of 19.7 minutes on each flight.
This is almost twice as long as delays at the best performing airport, London Heathrow, where each plane is delayed by an average of 11 minutes.
According to the punctuality figures Gatwick, Jersey and Durham Tees Valley were the next worst performing airports.
Scheduled and charter flights, but not cancelled services, from the 25 busiest airports were examined in the study.
The Press Association said flights across all airports left an average of 15 minutes late.
Leeds Bradford, Belfast City and London City were also among the top performers.
The CAA said the data allows passengers to “make informed choices about which airports they fly from”.
A Luton airport spokeswoman said factors outside its control had an influence on punctuality including air traffic control strikes, late arriving aircraft, bad weather and congested airspace.
Worst airports for punctuality:
Luton – 19.7 minutes
Gatwick – 18.9 minutes
Jersey – 18.7 minutes
Durham Tees Valley – 18.6 minutes
Birmingham – 18.2 minutes
Bristol – 17.6 minutes
Belfast International – 16.7 minutes
Manchester – 16.7 minutes
Stansted – 16.7 minutes
Aberdeen – 16.1 minutes
Edinburgh – 15.8 minutes
Cardiff – 15.7 minutes
Glasgow – 15 minutes
Doncaster Sheffield – 14.3 minutes
Liverpool – 14 minutes
Southend – 13.5 minutes
Southampton – 13.5 minutes
East Midlands – 13.3 minutes
Newcastle – 12.8 minutes
Bournemouth – 12.3 minutes
Exeter – 11.9 minutes
London City – 11.6 minutes
Belfast City – 11.3 minutes
Leeds Bradford – 11.3 minutes
Heathrow – 11 minutes
Average delay times in 2017 based on Civil Aviation Authority data, compiled by the Press Association