Travelers walk with their luggage at San Francisco International Airport on July 01, 2022 in San Francisco, California.
CNN  — 

Air traveler complaints in June were up a whopping 270% from pre-pandemic levels, according to new US Department of Transportation data released Monday.

Complaints from May to June of this year were up nearly 35% as airlines canceled thousands of flights in the beginning of the summer travel season, the data shows.

“In June 2022, DOT received 5,862 complaints about airline service from consumers, up 34.9% from the 4,344 complaints received in May 2022 and up 269.6% from the 1,586 complaints received in pre-pandemic June 2019,” the report states. “For the first six months of 2022, the Department received 28,550 complaints, up 27.8% from the 22,336 filed during the first six months of 2021 and more than the entire year of 2019.”

Earlier this month, Transportation Secretary Pete Buttigieg sent a letter to airlines telling them the level of disruptions this summer was “unacceptable.”

Buttigieg says the airlines need to make sure they are able to handle their schedules and improve their customer service when flights are canceled.

The DOT plans to post a new online dashboard by Labor Day weekend where passengers can find “easy-to-read, comparative summary information” on what each of the large US airlines provides to passengers when delays or cancellations are caused by factors within the airline’s control.

In a recent interview with CNN, United Airlines CEO Scott Kirby said his airline has been performing well and insists Federal Aviation Administration ground stops are impacting the airline’s operation.

“Frankly the bigger challenges are not the airlines themselves, it’s all the support infrastructure around aviation that hasn’t caught up as quickly,” Kirby said.

Buttigieg’s recent letter to airlines made only scant reference to the FAA’s issues with staffing at air traffic control facilities that have contributed to the cancellations and delays.

On August 15, a shortage of controllers prompted an FAA ground delay warning at New York’s big three airports.

Top image: Travelers walk with their luggage at San Francisco International Airport on July 01, 2022 in San Francisco, California. (Justin Sullivan/Getty Images)