Airlines canceled thousands of flights over Memorial Day weekend and it shows why carriers are trimming summer schedules

• Airlines had a rough Memorial Day weekend, canceling or delaying thousands of flights.
• Delta Air Lines canceled over 700 flights, blaming bad weather, air traffic control, and COVID-related sick calls.

Another holiday weekend has come and gone, but not without causing chaos for airlines and passengers.

Travelers flying over Memorial Day weekend faced a slew of delays and cancellations across the country, with over 2,500 flights total canceled since Friday, reported Reuters. According to flight-tracking website FlightAware, over 400 flights traveling within, out of, or into the US were canceled on Monday alone, while about 2,400 were delayed.

The carrier with the most issues was Delta Air Lines, which canceled around 700 flights over the long weekend. The carrier told Insider it was "enacting cancelations at least 24 hours in advance of departure time wherever possible," and accommodated over 90% of impacted customers on later flights.

The carrier blamed the disruptions on air traffic control issues, weather, and COVID-related sick calls, according to a research note from Cowen analyst Helane Becker, which was shared with Insider.

Other carriers like American Airlines and JetBlue Airways also faced holiday weekend challenges. American told Insider that severe thunderstorms in Miami caused most of the flight disruptions, forcing the carrier to cancel over 100 flights on Monday, per FlightAware data.

JetBlue suffered mostly from delays, with 25% of its schedule delayed and only 1% canceled on Monday, according to FlightAware.

The chaos comes as airlines trim their flight schedules to better manage the busy summer travel season. On Thursday, Delta announced it was cutting about 100 daily flights from July 1 to August 7 due to surging demand, saying the adjustments will "build additional resilience in our system and improve operational reliability for our customers and employees."

"More than any time in our history, the various factors currently impacting our operation – weather and air traffic control, vendor staffing, increased COVID case rates contributing to higher-than-planned unscheduled absences in some work groups – are resulting in an operation that isn't consistently up to the standards Delta has set for the industry in recent years," chief customer experience officer Allison Ausband said in the announcement.

Airlines like JetBlue and Alaska have also made changes. In April, JetBlue told CNN it was nixing 8% to 10% of its May flights. Alaska Airlines also cut summer flying by 2% through June, though the Seattle-based carrier did not face mounting delays or cancellations over the holiday weekend.

Memorial Day is just the start of what analysts say will be a hectic summer travel season. According to USA Today, experts anticipate 2022 passenger volume to surpass 2019, but staffing shortages across the industry have led to mass cancellations.

"We expect a busy summer, and are concerned about the industry's ability to handle the demand," Becker wrote. "We also expect ticket prices to be high through the summer as demand exceeds supply. The lack of crew members means smaller cities will continue to lose service and pricing should be strong through at least Labor Day."

The pilot shortage, in particular, has forced airlines to drop some regional flying, Bloomberg reported, with United Airlines grounding 100 regional jets due to a lack of pilots.