Chattanooga Metropolitan Airport traffic is moving higher, but the airlines are still flying less than half the number of passengers than a year ago due to the coronavirus-fueled downturn.

In September, the airlines boarded 17,738 passengers in Chattanooga, down 63.6% from a year ago, according to the airport.

Through the first three quarters of 2020, boardings were 163,698, or off 59.8% from the same period in 2019, airport figures show.

Nationally, the number of passengers screened in a single day for flights topped 1 million on Sunday for the first time since COVID-19 infections began to spike in March, according to The Associated Press.

The million-plus passengers screened Sunday compares with 2.6 million on the same day last year, or roughly 60% fewer, the Transportation Security Administration reported.

Terry Hart, the Chattanooga Airport's chief executive, told the Airport Authority on Monday that September boardings were 11% higher than in August. Boardings in August were 11% above July, he said.

"We've been continuing that steady upward trend," he said.

Hart said United Airlines is adding a second roundtrip between Chattanooga and Chicago, and the airline recently began direct flights to Houston.

In addition, he said, Delta Air Lines in the two weeks around Thanksgiving plans to return flying larger, mainline jets from Chattanooga to Atlanta. He said the airline will offer those aircraft on its 6 a.m., 7 a.m. and 8 a.m. departures from Chattanooga.

"They're starting to see an increase in their bookings," Hart said.

Authority member Paul Conn said he's flown on Delta four times since the pandemic began and felt "very comfortable" in terms of social distancing on flights in Atlanta. But, he said, not so much on the smaller aircraft in and out of Chattanooga.

Hart said the airline is booking at 60% capacity due to the coronavirus. Still, he said, it's hard to create a lot of space on the smaller aircraft.

"I'm glad to see the three morning flights," the airport CEO said.

Dan Jacobson, the Airport Authority chairman, said the pandemic continues to threaten the economy, but he's encouraged by the rising numbers of passengers.

"The new nonstop service to Houston and the Chicago service are both integral to rising enplanements," he said.

Jacobson said that construction on the airport's planned $25 million parking garage is coming out of the ground to handle traffic as it rebounds.

Also, the airport is designing an expansion of its terminal which would enlarge the security checkpoint area, add gates for arriving and departing aircraft, increase bathrooms in the terminal and boost concessions. But, the airport hasn't financially committed to that project yet.

Contact Mike Pare at Follow him on Twitter @MikePareTFP.