Memorial Day weekend flight cancellations top 4,500 and counting, disrupting passengers' plans amid ramp-up in holiday travel

• Flight delays and cancellations are disrupting many travelers' plans over the holiday weekend.
• More than 1,100 flights were canceled Sunday as of early afternoon, heading into Memorial Day.

Thousands of flight delays and cancellations are throwing a wrench in many passengers' travel plans this holiday weekend.

More than 4,500 flights from airlines around the world have been canceled since Friday. Airlines canceled 1,100 additional flights Sunday as of early afternoon, according to flight-tracking site FlightAware. This follows 2,300 cancelations on Friday and 1,500 on Saturday, the Associated Press reported.

Of the flights canceled Sunday, more than 300 of those were flights within, into, or out of the US, FlightAware data shows.

Among major US carriers, Delta Air Lines reported the most disruptions in recent days. On Saturday, the company canceled roughly 250 flights, or 9% of its flight schedule, and delayed 530 flights, or 19% of its total for the day, according to FlightAware. As of early Sunday afternoon, Delta has canceled 150 flights and delayed 150 for the day.

Delta told Insider on Saturday the airline is trying to give customers 24-hour notice of cancellations when possible.

"In addition to the factors outlined in our news release, our schedule today reflects heavy impact from adverse weather and air traffic control actions yesterday," the company said in a statement.

In an additional statement on Sunday, Delta said it "notifies customers through Fly Delta App notifications, email and text message, and automatically rebooks them on the next best available option to their final destination."

Delta Chief Customer Experience Officer Allison Ausband said in the Saturday press release that there are several factors impacting the airline, including labor shortages, a rise in COVID-19 rates among staffers, and weather and air traffic control.

"More than any time in our history, the various factors currently impacting our operation ... are resulting in an operation that isn't consistently up to the standards Delta has set for the industry in recent years," Ausband said.

The disruptions come amid a particularly fraught time for the industry, coinciding with a boom in air travel heading into Memorial Day. More than 3 million people are expected to fly this holiday weekend, compared to 2.4 million people last Memorial Day weekend, according to AAA.

Nearly 2 million people passed through Transportation Security Administration (TSA) checkpoints Saturday, up from 1.6 million at the same time last year, according to agency data. On Friday, TSA screened nearly 2.4 million passengers, up from almost 2 million at the same time in 2021.

Amid growing demand, however, airlines are grappling with staff shortages. Carriers like Delta, JetBlue, and Alaska Airlines have made cuts to their flight schedules for the summer due to staffing challenges, among other factors.

Some airlines have even resorted to reducing training requirements for pilots to help plug the shortage.