Midyear surge pushes O’Hare ahead of Atlanta for busiest airport crown, but will it stick?

Six months into 2025, O’Hare International Airport is the bride, not the bridesmaid, of U.S. aircraft operations, preliminary Federal Aviation Administration data shows.

O’Hare handled 407,290 operations between Jan. 1 and June 30, compared to rival Hartsfield-Jackson International Airport’s 398,629, a 2% difference.

The numbers mark “a milestone that positions Chicago to potentially reclaim the title of the world's busiest airport by operations for the first time since 2019,” Chicago Department of Aviation Communications Director Kevin Bargnes said.

“This ongoing momentum reflects the strength of Chicago’s aviation system and the deep commitment of our airline partners to the Chicago market.”

Hartsfield-Jackson took the lead during the COVID-19 pandemic in 2020 and hasn’t let go since.

“There's a strong tailwind behind O'Hare's traffic right now, with United Airlines growing particularly rapidly,” DePaul University aviation expert Professor Joseph Schwieterman said Tuesday.

The third-busiest facility midyear was Dallas Fort Worth, followed by Denver and Las Vegas’ Harry Reid airports.

Will that momentum continue for Chicago?

“A remarkable aspect of the situation is that there's little sign that the growth will stop anytime soon. Expect considerably more international flying next summer,” Schwieterman said.

“The payoffs from the O'Hare Modernization Program are now being realized more than ever, with flight activity surging during the summer peak,” he added.

Bargnes noted “the sustained growth in flight operations and passenger volume underscores the critical need for continued investment to ensure O’Hare remains a world-class global gateway for generations to come.”

The O’Hare Modernization Program involved constructing a parallel runway system. Now, the city is immersed in a massive building program that includes a new Global Terminal replacing Terminal 2 and two satellite concourses.

“Mayor Brandon Johnson has made advancing the airport's redevelopment a top priority, beginning with the groundbreaking of the first satellite concourse, scheduled for later this summer,” Bargnes said. “This milestone marks the start of a new era of modernization at O’Hare.”

In 2024, Atlanta notched up 796,224 flights to O’Hare’s 776,036.

“This growth would not be possible were it not for new gates at Terminal 5, which is relieving pressure on Terminals 2 and 3,” Schwieterman said.

“The only caveat to the numbers is that the average size of passenger airplanes at O'Hare remains small compared to other top-ranked airports,” he added. “Airlines, particularly United, are shifting toward larger equipment but this is taking time.”