By David Shepardson

WASHINGTON (Reuters) -U.S. aviation regulators are forecasting nearly 313,000 flights over the seven-day Memorial Day holiday period, up 4.5% from 2022 and just below 2019 pre-pandemic levels.

The Federal Aviation Administration said the traditional seven-day kickoff to the busy U.S. summer travel season will surpass the 299,500 flights flown in the same period in 2022 but will not match the 321,000 flights in the same period in 2019.

On Wednesday, Delta Air Lines (NYSE:) estimated it will fly 2.8 million passengers for the upcoming Memorial Day holiday period, up 17% from 2022. On Tuesday, United Airlines said it was planning for its busiest Memorial Day holiday in more than a decade, forecasting nearly 2.9 million passengers between May 25 and May 30.

American Airlines (NASDAQ:) said it will fly 26,637 flights over the Memorial Day period and carry 2.9 million passengers.

Last year, airlines had a rough Memorial Day weekend compounded by bad weather, cancelling more than 2,500 flights over a four-day period.

The FAA in March agreed to requests by Delta and United to temporarily return up to 10% of slots and flight timings this summer at congested New York area airports and Washington National, citing air traffic controller shortages.

Some airlines are operating larger planes to compensate for fewer flights, a move that the FAA said gives airlines “the ability to reduce operations during the peak summer travel period, which are likely to be exacerbated by the effects of Air Traffic Controller staffing shortfalls.”

The FAA said its staffing at the New York Terminal Radar Approach Control remain below targets. Last summer, there were 41,498 flights from New York airports where air traffic control staffing was a contributing factor in delays.

Earlier this month, the FAA said it activated 169 more direct routes along the U.S. East Coast ahead of the busy summer travel season, shaving off 40,000 miles and 6,000 minutes of travel time.