Within in the U.S., the average flight arrives 14 minutes after a scheduled arrival. Approximately 7% of all flights arrived more than an hour late.

USAFacts calculated the percentage of flights delayed – and the average length of those delays – at U.S. airports between October 2018 and September 2019 by looking at data from the U.S. Bureau of Transportation Statistics, part of the U.S. Department of Transportation.

At the nation’s 30 busiest airports, Newark Liberty International Airport takes the No. 1 spot with 26.5% of all flights taking off late, according to flight data. Newark also had the longest average delay time – 22 minutes per flight. The No. 2 spot goes to New York’s LaGuardia Airport with 24.5% of all flights leaving late and averaging 19.6 minutes per flight delay.

Other airports with the worst flight delays include: Chicago O’Hare International Airport with 25.5% of all flights leaving late (19.2 minutes per flight delay); Boston’s Logan International Airport (22% of all flights delayed, 17.3 minutes per flight delay); Dallas Fort Worth International Airport (23.3% of all flights delayed, 16.5 minutes per flight delay); San Francisco International Airport (22.4% of all flights delayed, 16.2 minutes per flight delay); Fort Lauderdale-Hollywood International Airport (21.9% of all flights delayed; 16.3 minutes per flight delay); Denver International Airport (21.6% of all flights delayed; 15.3 minutes per flight delay); Miami International Airport (21.6% of all flights delayed; 15.3 minutes per flight delay); Chicago Midway Airport (22% of all flights delayed; 13.4 minutes per flight delay).

Poor weather conditions, late aircraft, carrier related (baggage, fueling, or maintenance problems), and airspace system issues make up the top reasons for flight delays, according to USAFacts. Late aircraft is the most common cause for flight delays.

With a lot of flights in the summer, the summer months have the highest average flight delays. July has the highest delay of 76 minutes followed by June with an average of 72 minutes and August with an average of 71 minutes. 

Honolulu International Airport was named as the top airport with the fewest delays with 10.5% of all flights leaving late and an average of 6.8 minutes per flight delay. Anchorage International Airport came in second with 11% of all flights delayed and an average of 7.1 minutes per flight delay.

The Department of Transportation identifies a late flight as a plane arriving at least 15 minutes after its scheduled arrival.