Hawaiian Airlines has been knocked off its perch — for one month anyway — as the nation’s most punctual carrier.

The state’s largest airline completed 88.8 percent of its flights on time in July to rank second behind Alaska Airlines, which had 89.4 percent of its flights arrive within 14 minutes of their scheduled arrival, according to data released Tuesday by the U.S. Department of Transportation.

This was the first time since October 2015 that Hawaiian hasn’t been ranked first in on-time performance. In that month, Hawaiian was second to Delta Air Lines.

Still, Hawaiian ranks first over the past 12 months and has led all U.S. carriers in on-time performance for each of the past 12 years starting in 2004.

The DOT said 75.2 percent of flights on the 12 largest U.S. airlines were on time during July. That’s down from 78 percent in June and 78.1 percent the previous July. Frontier Airlines had the worst performance, with only 63.3 percent of its flights arriving on time.

The biggest four airlines finished in the middle of the pack, with Delta best in the group, followed by United, Southwest and American.

The rankings include the 12 U.S. air carriers that have at least 1 percent of total domestic scheduled-service passenger revenue and covers nonstop scheduled-service flights between points within the United States, including territories.

Twenty-one flights were stuck on the ground longer than federal rules allow — three hours for domestic flights, four for international ones, according to the report.

Eight of the long delays were on Delta or Delta Connection and five were on United.

It was the highest monthly number of long delays in more than a year — since there were 24 in February 2015 — and it could mean fines for the airlines involved.

In other categories, Hawaiian ranked second in fewest flight cancellations for the month with 0.2 percent, representing 16 cancellations out of 7,022 flights. Hawaiian also ranked fifth for fewest mishandled baggage reports with 2.47 per 1,000 passengers and was seventh for fewest consumer complaints with 1.38 per 100,000 passengers.

For the 12 carriers, nearly 2 percent of all flights were canceled, including 2,300 on Southwest in the days after a computer outage. The cancellation rate nearly doubled from June.

Consumer complaints filed with the government continued to fall, and represented a tiny fraction of the millions of airline passengers.

The Transportation Department said it received 1,963 complaints including 1,357 about U.S. airlines. The overall complaint rate fell 9 percent, complaints against U.S. airlines dropped 20 percent, and complaints about foreign airlines rose 19 percent compared with a year earlier.

The Associated Press contributed to this story.