6,000+ US flights canceled or delayed Friday after one of worst summer air travel days yet

Travelers are facing the second day of misery at airports across the country.

More than 1,300 U.S. flights were canceled as of 5 p.m. EDT Friday with over 5,000 more posting delays, according to FlightAware, which tracks flights in real time. 

The headaches come on the heels of one of the worst travel days yet as the peak summer vacation season heats up. More than1,750 U.S. flights were canceled Thursday.

►LATEST UPDATES FROM SATURDAY:US flight cancellations, delays continue: More than 2,700 flights affected so far

Nationwide, American Airlines and Delta Air Lines have the most cancellations so far, with their schedules reduced by 8% and 7%, respectively, Friday. Those numbers do not include flights on their regional affiliates, which operate as American Eagle and Delta Connection. 

"The vast majority of that is weather-related," said Curtis Blessing, spokesman for American Airlines. He noted that weather in the Miami area was also contributing to delays for the carrier on Friday morning.

Airlines kicked off the busy summer travel season by canceling about 2,800 flights in a five-day stretch around the Memorial Day holiday weekend, marking the start of what's likely to be a tough summer for the nation's air passengers. 

Thursday and Friday's issues come in the wake of a virtual meeting between airline CEOs and Transportation Secretary Pete Buttigieg – a sign of the Biden administration's concern about the prospect of snarled airports and unhappy travelers this summer.

“I let them know that this is a moment when we are really counting on them to deliver reliably for the traveling public,” Buttigieg told NBC News.

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What travelers need to know

If your flight is canceled, the U.S. Department of Transportation requires airlines to rebook you on their next available service with space. If that will not work for you, the carrier is required to offer you a refund, even if you bought a nonrefundable ticket.

In the event of a delay, an airline's responsibility is a little less clear. DOT does require compensation for "significant delays" but has no official definition for what counts as "significant." 

Many airlines updated their policies during the pandemic to give travelers more flexibility in rebooking or altering plans. Delta, for example, automatically rebooks passengers whose flights were canceled and sends them their new itineraries via email, text and the Fly Delta App. Customers are free to change their rebooked flight online or via Delta's digital messaging platform if the new itinerary doesn't work. 

So far, airlines are not issuing preemptive change fee waivers in response to Friday's cancellations, but affected passengers will still have options to rebook.

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Why this summer is tough for travel

As COVID-19 restrictions continue to loosen, more Americans are planning to venture away from home this summer, but airlines have struggled to keep up with with the surge.

“I think every single part of the travel industry from the airlines to airport employees to security agents, they all just got caught flatfooted by this explosion in demand," said Kyle Potter, editor of the website Thrifty Traveler, which aims to familiarize people with the inner workings of the airline industry and find travel deals."It’s really easy to have 20/20 vision in hindsight and tell airlines and airports ‘You went way too far when travel collapsed in cutting back to the bone to stop losing money,'" but earlier in the pandemic, no one really knew how long the slump would last.

Around 50 Delta pilots protested in New York on Thursday, saying that by this fall they expect to have worked more overtime in 2022 than they did in 2018 and 2019 combined. 

And Delta is not alone in staffing woes. JetBlue recently announced a plan to cut 10% of its schedule this summer in response to expected shortages in its ranks. 

Travelers planning to fly this summer should make sure to check flight status with their airlines before heading to the airport and know their rights if something goes wrong. 

Contributing: Associated Press