The flight cancellations at airports across the U.S. are expected to persist even after the government shutdown ends.
The Federal Aviation Administration has reduced flights as some air traffic controllers — unpaid for weeks — have stopped showing up for work.
"I mean, no question, things are getting worse," says Thrifty Traveler's Kyle Potter who has been tracking the cancellations all weekend. "I'll put it this way, Sunday was the worst day in air travel, and one of the worst days, I'll put it that way, in the last two years. And that is not an a thing you can isolate when you have that bad of a day for the entire U.S. airline industry, especially a hometown carrier like Delta, which was by far the worst. That is going to have a spillover effect into Monday."
Nearly 3,000 flights were canceled and at least 10,000 flights delayed on Sunday, according to data from FlightAware.
The Senate took a first step toward ending the shutdown Sunday, but final passage could still be several days away. Transportation Secretary Sean Duffy made clear last week that flight cuts will remain in place until the FAA sees safety metrics improve.
Over the weekend, airlines canceled thousands of flights to comply with the order to eliminate 4% of flights. The cancellations are scheduled to rise to 6% of all flights at 40 of the nation's busiest airports on Tuesday. By the end of the week, flight cancellations are scheduled to reach 10% of all flights at those airports.
Even if there's a fast end to the government shutdown, Potter says the chaos is not going away immediately.
"Disruptions are going to continue for probably the better part of the week," he explains.
Already, travelers are growing frustrated.
“All of this has real negative consequences for millions of Americans, and it’s 100% unnecessary and avoidable,” said Todd Walker, whose flight from San Francisco to Washington state was canceled over the weekend, causing him to miss his mom's 80th birthday party.
As of Monday morning, airlines had already canceled 1,600 flights for Monday and nearly 1,000 for Tuesday. International flights have not been affected.
Beyond the mandated cuts, flight delays have been rippling through airports nationwide at times ever since the shutdown began. That's because the FAA slows air traffic anytime it's short on controllers at one of its facilities to ensure flights remain safe.
Tuesday will be the second missed payday for air traffic controllers and other FAA employees. It's unclear how quickly they might be paid once the shutdown ends. The head of the controllers union, Nick Daniels, plans a news conference Monday morning to address the shutdown's toll.
“More controllers aren’t coming to work day by day, the further they go without a paycheck,” Duffy said.
The government has struggled for years with a shortage of air traffic controllers, and Duffy said the shutdown has worsened the problem, prompting some controllers to retire early or quit. Before the shutdown, Duffy had been working to address the shortage by hiring more controllers, speeding up training and offering bonuses to retain experienced controllers.
Duffy warned over the weekend that if the shutdown drags on, the situation could deteriorate further as the U.S. heads into the busy holiday travel season. He said air travel may “be reduced to a trickle” by the week of Thanksgiving.
"I do think that, as long as this deal gets through Congress and paychecks go out to air traffic controllers and TSA agents, we're going to avert the worst of the worst of truly widespread disruptions over that Thanksgiving holiday travel week," Potter said on the WCCO Morning News Monday.
Sec. Duffy has also said that this is going to have longer impacts that are going to stretch not just into Thanksgiving week, but probably even further than that.
"This really put an already incredibly short-staffed air traffic control workforce, even further behind than where it was going into the shutdown," says Potter. "So I think everybody is going to have to be a little bit more comfortable with the fact that air travel is going to be bumpy, not just through the rest of the week or the month, but probably for a little while. Because this is going to take some time to dig out of."
Federally mandated flight reductions remain in place - for now - and those will increase from 4% to 6% on Tuesday, making a bad situation even worse. If no agreement is reached to end the shutdown, that will be eventually scaling up to 10% by the end of the week per the Federal Aviation Administration.
If the shutdown continues? Expect pure chaos and just a trickle of flights actually getting out as we close in on Thanksgiving week, one of the busiest travel times of the year.
Potter says one thing travelers need to think about is a backup plan, before you show up at the airport.
"If you have those backup options in mind, you are ahead of the curve to go up to that airline agent and say, 'here's the flight that I want to be put on. Can you make it happen?'"
The Associated Press contributed to this story.