Airfare will remain below 2023 levels through the end of the year, but will start to rise as the fall and winter holiday seasons approach.

According to a forecast from booking site Hopper, domestic airfare is expected to average just $240 roundtrip in September, 8 percent lower than the same time period last year. In the report shared with Travel + Leisure this week, Hopper predicted that prices will remain below 2023 levels through the end of the year despite a record-setting summer, but will nonetheless begin to rebound in October as travelers start to think about the Thanksgiving and Christmas holidays.

Airfare costs in the United States are expected to peak during the second week of December and average about $283 roundtrip. However, that is still 9 percent lower compared to the same time period last year. 

"After a summer of travel packed with record breaking passenger traffic days, as Americans head back to work and school, we enter the fall 'shoulder season' which sits between the peak summer travel months and the busy holiday travel season,” Hayley Berg, the lead economist at Hopper, told T+L. “Seasonally, we see lower bookings during this period which means lower prices and more deals are available for those travelers with flexibility to travel after the summer season ends.”

Airfare is expected to once again drop in January with an average ticket cost forecast to come in as low as $251.

To explain the overall lower costs, Hopper pointed to airlines increasing capacity, with the site noting that airlines flew about 94.5 million seats in July, an increase of 6 percent compared to last year. Indeed, several airlines have announced large expansions recently, including United Airlines, Alaska Airlines, Delta Air Lines, and more. 

Low costs also extended to international destinations. In fact, Hopper said fall fares to destinations like Canada, Europe, South America, and more have dropped below 2019 levels.

However, the exception to that is travel to Asia, which remains about 36 percent above 2019 prices.