The total number of flight cancellations within, to or from the United States as of 6:07 a.m. ET was 669, according to flight tracking website Flightaware.com https://uk.flightaware.com/live/cancelled /today. Nearly 860 flights were canceled on Sunday.
Delta Air Lines, United Airlines Holdings Inc and Republic Airlines Inc recorded more than 100 cancellations each, while American Airlines Group Inc canceled 51 flights early Monday.
The companies did not immediately respond to a request for comment.
In Europe, recent airport traffic jams have been blamed on a shortage of employees, as many workers, who were laid off during the pandemic, are abandoning airport work for flexible working practices and other occupations.
Even the US regulator, the Federal Aviation Administration (FAA), is facing a staff shortage.
Last week, the FAA granted United permission to temporarily reduce flights to Newark after the Chicago-based carrier requested a waiver, citing airport construction and air traffic control staffing.
Airlines for America, a trade group, said Friday that the FAA must ensure adequate air traffic control personnel to avoid further summer travel disruptions.