Southwest Airlines canceled hundreds more flights Monday, including multiple flights in Philadelphia, following a weekend of service disruptions that left travelers stranded across the country.

According to the flight-tracking website FlightAware, the carrier had canceled more than 350 flights by Monday afternoon and delayed more than 1,000 flights. On Sunday, it canceled 1,124 flights, or 30% of its U.S. schedule, with eight coming into and out of Philadelphia.

The Dallas-based airline blamed air traffic control issues and weather. Southwest was the only airline to report the issues on that scale.

The chaos has left some Philadelphians helpless, forced to take on costly hotel stays as they face multiple flight cancelations.

Jessica Welhaf, 29, has been stuck in Florida since Saturday and forced to foot hundreds of dollars for lodging and meals after her connecting flight to Philadelphia was canceled.

Welhaf, of Bensalem, was flying home from Minneapolis on Saturday from a monthly work trip. As her connecting flight approached its gate in Orlando, she was alerted that “due to a crew issue,” the flight was canceled. After navigating long lines and a nearly eight-hour wait on the phone with customer service, Welhaf was eventually scheduled on a flight back to Philly for Monday morning. Other available flights on short notice were upward of $1,000, she said, and the airline did not offer vouchers for food or hotels, which were filling up fast.

She found a hotel a few miles away for $100 a night, but as she packed up her belongings early Monday, she was notified that her latest flight was canceled, too. She was told she was rescheduled on a Thursday flight — six days after her initial flight.

“Any expense that I incur, I don’t know if I can actually get it back, and that’s really hard, because I can’t afford to just throw money away,” she said.

Out of desperation, Welhaf purchased a $56 Greyhound bus ticket from Orlando to Miami on Monday afternoon, where, after the five-hour ride, she’ll stay with family. She found a $225 American Airlines flight back to Philadelphia from Miami on Tuesday.

She estimated that she’ll have spent at least $700 on food, ridesharing, and accommodations by the time she gets home.

“If I wanted to take a vacation to Orlando, I would have done it myself,” she said.

Southwest struggled all summer with high numbers of delayed and canceled flights. In August it announced it was trimming its September schedule by 27 flights a day, or less than 1%, and 162 flights a day, or 4.5% of the schedule, from early October through Nov. 5.

Last week, Southwest became the latest airline to announce it was requiring its staff to be vaccinated against the coronavirus. The company said its workers must be fully vaccinated by Dec. 8 in order to remain at the airline. Employees can seek approval to skip the shots because of medical or religious reasons.

Though some speculated that the outages reflected a work slowdown by pilots opposed to the mandate. the airline and the pilots’ union denied that.

“The weekend challenges were not a result of employee demonstrations, as some have reported,” said a statement from Southwest Airlines spokeswoman Brandy King. Southwest blamed the problems on bad weather and air-traffic issues in Florida, which it said had displaced crews and aircraft.

Union leader Casey Murray, president of the Southwest Airlines Pilots Association, said there had been no job action.

“We have the data from this weekend and our sick rates were exactly in line with where they were all summer with the same kind of operational disasters,” Murray said.

The Dallas Morning News contributed to this article.