Don’t get to the airport late.

The advice is more important this Thanksgiving than it has been in years—maybe in decades, travel experts say.

More Americans are expected to travel for Turkey Day than in at least the past three years. The numbers could exceed Thanksgiving 2019, the last before the COVID-19 pandemic ground travel to a halt.

That year’s Thanksgiving weekend was the second busiest since 2000.

More than 43 percent of adults, about 112 million people, plan to travel for Thanksgiving this year, up from 42 percent last year, according to The Vacationer, a travel website.

Nearly 25 million seats are scheduled to depart on flights between Nov. 20 and Nov. 27, a 6 percent increase from 2019, according to Hopper.com, another travel website.

The Sunday before Thanksgiving, Nov. 20, is expected to see about 3.3 million people in airports.

On Nov. 27, the Sunday after Thanksgiving, traveler numbers are predicted to peak at 3.4 million as people return home from their trips, according to Hopper.

According to the report, hub airports in Atlanta, Dallas Fort-Worth and Denver are expected to be the busiest that week, with over 1 million travelers each.

“If you’re departing from one of these airports, be sure to get to the airport early, expect longer lines and be prepared for potential delays,” the report said.

The two quietest travel days in the holiday week are Thanksgiving Day and Black Friday, the day after the holiday.

From Nov. 21-27, Pittsburgh International Airport is expected to see nearly 100,000 departing passengers and another 100,000 arriving passengers. Like the rest of the country, the Sunday after Thanksgiving is expected to be the busiest day, with Nov. 23, the day before being the second busiest.

Each of those days has nearly 4,000 passengers departing PIT before 7 a.m., so travelers are being asked to arrive extra early those days as security lines may be very busy.

End of turbulent year

The expected surge in holiday travel comes in the aftermath of a chaotic summer when air travel rebounded—and then surpassed—levels higher even than the summer of 2019.

As it was in the peak summer months of May through August, holiday travelers are likely to face delays at boarding gates, limited flight availability and misplaced luggage.

Complaints to U.S. Department of Transportation this summer were more than three times higher than in 2019. By summer’s end, airlines had canceled about 146,000 flights, 2.6 percent of all flights. Nearly 1.3 million flights had been delayed, according to tracking service FlightAware.

The rate of cancellations is up about one third from the same period in 2019, before the pandemic, and the rate of delays is up nearly one fourth.

Airlines still face a shortage of pilots and other workers. And winter weather and more demand for flying during the six weeks from Thanksgiving to the end of the year may add to travelers’ problems.

United Airlines CEO Scott Kirby said that, along with the insufficient number of pilots, carriers are still need more aircraft as pandemic-induced supply chain problems caused Boeing Co. and Airbus SE to fall behind in production.

Meanwhile, demand for air travel continues to grow, helped by the combination of working from home and office policies that allow people to travel more, he said in an Oct. 19 interview with Bloomberg Television.

“It’s just a new, permanently higher level of demand,” Kirby said. “That makes every weekend a potential holiday weekend.”