Delta Air Lines, trying to get back to normal after thunderstorms wreaked havoc on flight schedules, had to scrub about 120 more flights Sunday.
"The operation continues to stabilize ... as things normalize," said Michael Thomas, a spokesman for the No. 2 US airline.
Delta had canceled around 3,275 flights through Saturday after powerful mid-week storms stranded and frustrated passengers during one of the busiest travel weeks of the year.
Delta Chief Operating Officer Gil West called the storms that pounded Atlanta "unprecedented" and acknowledged the recovery effort could have been better.
The severe weather battered the mid-Atlantic region, the Northeast and Georgia, causing tornado-like conditions around Delta's hub, Hartsfield-Jackson International Airport in Atlanta, through which 60% of its 1,250-aircraft fleet passes each day.
Delta has one of the most enviable track records in the airline industry. The carrier had 161 days in 2016 without a cancellation on its mainline operations.
Several factors aggravated the recent air-travel headaches, including planes packed with vacationers on spring break.
The airline and travelers should be helped by the weather, as forecasts call for a mostly rain-free week in the Atlanta region, with showers expected Wednesday and Friday.