• US airlines canceled over 1,200 flights from Friday to Sunday over the July 4th holiday weekend.
  • Disruptions eased by Monday afternoon with fewer than 130 flights canceled by major US carriers. 
  • Bad weather and staffing issues contributed to the holiday weekend chaos.

Travelers can breathe a sigh of relief as flight disruptions ease after a weekend of mass cancelations.

Since the start of the July 4th holiday, US airlines have canceled or delayed over 16,500 flights flying within, into, or out of the US, according to data from flight-tracking website FlightAware. This includes about 1,250 flights canceled and another 15,400 delayed from Friday to Sunday.

American Airlines and Delta Air Lines fared the worse, with both canceling about 250 flights each, or 3% of their schedule, according to FlightAware. Meanwhile, United Airlines canceled 120, or about 2% of its flights.

Despite the chaos, FlightAware shows that US airlines are getting back on track after a rough weekend, with United, American, and Delta canceling 42, 42, and 38 flights on Monday, respectively, at the time of publication.

This compares to 51, 28, and 54 flights that were canceled on Sunday, respectively, while 43, 104, and 81 flights were canceled on Saturday, per FlightAware. Southwest Airlines had only canceled six flights on Monday at the time of publication.

Bad weather and staffing shortages contributed to the chaos, per CNN, but former airline pilot and FlightAware spokesperson Kathleen Bangs said pilot and air traffic control (ATC) staffing are the biggest factors.

"Weather has always impacted aviation, but the weather so far this summer hasn't been any worse than normal," she told CNN. "When we see severe weather, it is taking airlines longer to scramble and recover. They don't have the deep bench of pilots to call in. It really seems to be more of a systemwide staffing issue, trickling down to FAA in terms of air traffic control system."

United CEO Scott Kirby told Bloomberg in June that ATC staffing at its Newark Liberty International Airport hub has caused massive disruptions, saying there are days when it is at 50%.

The Federal Aviation Administration told Insider that the agency "does not have a system-wide air traffic controller shortage" but has placed more controllers at facilities in Florida to support the increased travel demand.

The Jacksonville Air Route Traffic Control Center, in particular, has faced staffing problems over the months, with airline lobbying group Airlines for American (A4A) saying the facility has been understaffed for 27 of the last 30 days as of June 24

A4A called on Transportation Secretary Pete Buttigieg to address the staffing issues ahead of the July 4 holiday, saying the shortages have "led to traffic restrictions under blue-sky conditions."

Buttigieg has warned of punishments for airlines if operations are not improved. Meanwhile, Senator Bernie Sanders called on cabinet member to fine carriers $55,000 "per passenger for every flight cancellation they know can't be fully staffed."

The past three holiday weekends have proved to be hectic for US carriers, with about 3% of flights canceled over Memorial Day and 4% canceled over Juneteenth, per FlightAware. According to CNN, airlines did not typically see more than 1% of flights canceled in 2019.

Henry Harteveldt, travel analyst and president of Atmosphere Research Group, told Insider the situation was not expected to improve, especially as shortages continue.

"The system doesn't bend anymore when there's a problem," he said. "It just snaps."

Read the original article on Business Insider