U.S. airlines started the year showing a slight improvement in keeping flights on time.
The Transportation Department said Thursday that 79.6 percent of flights in January arrived within 14 minutes of schedule, compared with 76 percent in the same month last year.
But January's performance was worse than December, when 80.3 percent of flights arrived on time.
Alaska Airlines posted the best on-time rating at 88.9 percent, while JetBlue Airways was last at 65.8 percent.
Twelve domestic flights sat on the ground at least three hours, long enough to risk fines by the government. Delta and JetBlue had three each.
Airlines canceled 3 percent of domestic flights in January, up from 2 percent a year earlier and 1.2 percent in December.
The highest cancellation rates were on regional carriers that operate smaller planes on flights for the major carriers. PSA Airlines, a subsidiary of American Airlines, canceled 7 percent of its flights, while Delta subsidiary Endeavor Air scrapped 6.1 percent. JetBlue canceled 5.9 percent of its flights.
Complaints to the government about U.S. airlines fell to 703 in January from 1,005 a year earlier. Spirit Airlines, Frontier Airlines and Allegiant Air had the highest complaint rates, while ExpressJet, Alaska and Republic had the lowest.
The monthly Transportation Department report has been expanded to cover 18 airlines including Allegiant and several carriers that operate flights for American Eagle, Delta Connection and United Express.