Airline delays and cancellations are up slightly from last year's peak travel season.

The U.S. Department of Transportation said Thursday that flights on the nation's largest airlines arrived on time 77.7 per cent of the time in August. That is down from 78.8 per cent in the same month last year, although it is better than July.

The 14 airlines covered in the government report cancelled 1.2 per cent of their U.S. flights in August, up from 1.0 per cent a year earlier.

The airlines blame bad weather for an increase in delays and cancellations this year. The first six months of 2014 were the worst for delays since 2008.

Hawaiian Airlines, which benefits from good weather on much of its route network, held its usual place atop the rankings. Delta Air Lines was best among the largest carriers. American Airlines and one of its regional-flying subsidiaries, Envoy Air, had the worst on-time ratings. American did not immediately respond to a request for comment.

Only one domestic flight was delayed on the tarmac for more than three hours in violation of federal rules -- a Republic Airlines plane scheduled to fly Aug. 12 from Washington's Reagan National Airport to Columbus, Ohio. Such delays can bring fines. Nearly 300 flights were delayed more than two hours, which is permitted under the rules.

Virgin America ranked best at handling baggage; Envoy had the highest rate of lost, damaged, delayed or stolen bags -- nearly twice as high as any other airline.

Southwest Airlines had the lowest rate of consumer complaints to the government. Frontier Airlines had the highest.

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Here are the government's rankings of the leading airlines and their on-time performance for August. Some airlines, including Spirit and Allegiant, are not included because they operate fewer flights. The federal government counts a flight as on-time if it arrives within 14 minutes of schedule.

1. Hawaiian Airlines, 94.0 per cent

2. Delta Air Lines, 84.8 per cent

3. Virgin America, 84.3 per cent

4. Alaska Airlines, 83.8 per cent

5. AirTran Airways, 83.7 per cent

6. US Airways, 82.7 per cent

7. Frontier Airlines, 77.5 per cent

8. JetBlue Airways, 77.4 per cent

9. SkyWest, 76.9 per cent

10. United Airlines, 76.8 per cent

11. Southwest Airlines, 75.3 per cent

12. ExpressJet, 74.6 per cent

13. American Airlines, 73.2 per cent

14. Envoy Air, 70.1 per cent

Total for all reporting airlines: 77.7 per cent

--Southwest and AirTran are owned by Southwest Airlines Co.

--American, US Airways and Envoy are owned by American Airlines Group Inc.

--Envoy was formerly American Eagle

Source: U.S. Department of Transportation report