The busy July 4 holiday travel weekend started with thousands of flight delays as U.S. airlines continue to reel from staffing shortages.

Memorial Day weekend travelers at LAX

People are waiting in line for their flights.

Los Angeles Times via Getty Images

The busiest airports in the U.S. were the ones with the most flights that were delayed on Friday.

Almost a quarter of flights at BostonLogan and Philadelphia International were delayed.

The airlines delayed more flights on Friday than they did in April and June.

More than 30% of American Airlines flights were delayed, up 7 percentage points from the average delays from April to June, while Delta pushed back about a quarter of its flights Friday, up 6 points from its average rate.

Friday's total cancellation was 587.

The time is 10:30 a.m. There were 487 flights that were canceled.

PLAY Forbes Business Full Screen About Connatix Big Ten Swipes USC And UCLA From Pac-12 In Big Financial Coup Read More Monkeypox Symptoms Look Different In Recent Cases Than Previous Outbreaks, Doctors Warn Read More The Malcolm Brogdon Trade Shows The Boston Celtics Are Willing To Put Their Money On The Line Read More Read More Joe Joyce Vs. Christian Hammer: Odds, Records, Prediction Read More R. Kelly Placed On Suicide Watch Days After Prison Sentencing, Lawyer Says Read More 1/1 Skip Ad Continue watching after the ad Loading PodsVisit Advertiser websiteGO TO PAGE Big Ten Swipes USC And UCLA From Pac-12 In Big Financial Coup

There were 2.39 million. More than three times the number of people were screened at the airport on July 1, 2020 than on Friday, according to the transportation security administration.

During the busy July 4 travel weekend, airlines have been preparing for pre-pandemic levels of travelers as they struggle with staffing shortages caused by the swine flu. Carriers lost thousands of workers through early retirement and buyouts due to the coronaviruses. More than 7,000 flights were canceled over the Memorial Day holiday weekend and over 1,500 were canceled during the Juneteenth weekend due to the weather. Delta told passengers that they would not have to pay change fees and fair differences in order to travel on July 4. Passengers have complained in record numbers to the federal government about the flight disruptions, and Transportation Secretary Pete Buttigieg warned airlines to be prepared to support their tickets.

Further Reading

The airlines and airports have the highest rates of disruptions, but they are the least risky.

The summer travel chaos is caused by a pilot shortage.

The weekend flight cancelations top 1,500.