Air travel's return takes a hit as summer winds down, school is back in session, and the Delta variant continues to surge

• US air travel hit a 10-week low on Tuesday, according to TSA data.
• A TSA spokesperson said seasonal changes and typical travel patterns may be contributing to the drop.
• Airlines and Airbnb have cited the Delta variant as a concern affecting upcoming fall bookings.

The air travel industry has spent the first part of this year rebounding from lows during the COVID-19 pandemic, but the Transportation Security Administration recorded a 10-week low for air traveler throughput, or individuals at airport security checkpoints.

The TSA screened 1,607,238 air passengers on August 17, a 28% decrease from a summer high, which clocked in 2,238,462 traveler check-ins at the start of August.

The change was noted in a tweet from TSA spokesperson, Lisa Farbstein, who added, "It's still important to #MaskUp when traveling."

-Lisa Farbstein, TSA Spokesperson (@TSA_Northeast) August 18, 2021

Though the air travel industry is expected to remain below pre-pandemic levels in 2021, several signs pointed to a post-pandemic recovery boom at the beginning of this year. Airline, hotels, and restaurants saw customers spend more on travel as businesses reopened in the spring and summer. Remote work also allowed people to travel more while staying connected to the office.

This trajectory seems to be slowing down for now as the summer leisure travel season comes to a close and people return to work and school. Business travel is expected to slowly but gradually pick up again as we roll into the fall. The count also reflects Tuesday travel numbers, which Farbstein told Insider traditionally sees slower travel than other days of the week.

The drop may also account for an increasing concern over the spread of the COVID delta variant, which is continuing to spread across the US and remains a continuing threat for unvaccinated populations.

Southwest Airlines cited in financial filings that the impact of COVID Delta cases affecting a deceleration in bookings and a rise in cancellations in August. Frontier Airlines also saw a "softening" in seasonal bookings directly related to an increasing COVID case load. Travel stay companies, like Airbnb, also expect bookings to fall in the coming months due to the Delta variant.