The troubles followed thousands of other flight cancellations and delays in the United States going back to Thursday. Since then, almost 20,000 flights have been canceled or delayed.
"This has been another travel Armageddon weekend," InteleTravel President James Ferrara told USA Today. "But it's not isolated, or really a surprise."
There were new cancellations and delays by early Monday, as well -- but the number of canceled flights was under 300, according to FlightAware. There were about 1,700 delays. Newark Liberty International Airport, one of three major airports in the New York City metro area, had the most cancellations early Monday.
Staff shortages for airlines and severe weather came as air travel in the United States experienced its busiest days of the year so far -- with about 2.4 million passengers passing through airport security on Friday and another 2.1 million on Saturday.
"We're in a boom time for travel. We're blowing away all records, all previous years. So you've got this surge in demand, and you've got limitations on staffing," Ferrara said.
Air travel in the United States is expected to boom again in two weeks, when millions will travel over the Fourth of July weekend. The holiday falls on a Monday this year. File Photo by Bill Greenblatt/UPI
Jason Reisinger, American Airlines' managing director of global network planning, said the entire airline industry is trying to adjust schedules to accommodate rising passenger demand.
"[We are] working schedules early on so that there will be supportable early on so we have as few hiccups as we can on a given day," Reisinger told WRAL-TV, adding that American carriers are adding 12,000 pilots to fill backlogs.
"It takes a long time to get someone trained and up to speed and have enough flight hours to command one of these aircraft," he said. "So, how do we get ahead of the curve and just help people choose to do that?"
Air travel is expected to see another busy weekend around the Fourth of July in two weeks, which falls on a Monday this year. Millions of Americans are expected to travel over the preceding weekend and into the holiday.