Flight cancelations and delays eased across the United States on Monday as the three-day July 4th holiday weekend came to a conclusion.

Some 203 flights into or out of the United States were canceled and 1,616 others delayed as of late Monday afternoon, according to the airline tracking website FlightAware.

That compared with nearly 4,700 delays and 312 cancelations on Sunday, when United Airlines reported 55 flight cancellations and Delta Airlines scrubbed 53 scheduled flights.

The latest disruptions came as airlines and industry analysts anticipated the busiest weekend ever during a non-pandemic year as Americans sought to satisfy pent-up travel demands.

Concerns were heightened because the surge follows a month in which the United States surpassed its entire total for flight cancelations recorded during all of last year. FlightAware figures show 121,918 flights into or out of the United States were canceled as of the end of June, compared to 121,552 during all of 2021, Newsweek reported.

Airlines have blamed the flight disruptions in recent months on poor weather and air traffic control issues. The Industry group Airlines for America, responding last month to concerns voiced by the Biden administration, said air traffic control-related issues "were a factor in at least one-third of recent cancellations."

The group pointed to adverse weather requiring the Federal Aviation Administration to institute ground delay programs that slow the system "for many hours," as well FAA "staffing challenges" leading to traffic restrictions under blue sky conditions.

Those assertions, however, have been challenged by some congressional leaders.

During the first four months of 2022, carriers cancelled 3.5% of flights and delayed another 20% -- far above similar figures before the COVID-19 pandemic, according to Senate Democrats investigating the issue.

In the run-up to the holiday weekend, they cited data indicating that roughly 40% of delays so far this year "were due to circumstances within the airlines' control, the highest figure in over a decade."

Flight cancellations and significant delays "have real-world consequences for the travelers who may miss vacations, sacrifice time with loved ones, or incur significant financial costs," they wrote in a letter to the top U.S. carriers.

"If an airline cancels a flight for any reason, the airline must promptly provide passengers refunds, as required by the law," they added. "As the July 4th holiday approaches, the reliability of the air travel system should not be up in the air."

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