Over the Christmas weekend, thousands of flights were canceled because of inclement weather and staffing shortages resulting from surging coronavirus cases driven by the Omicron variant.
On Sunday, there were 3,274 cancellations and 16,305 delays, according to flight-tracking platform FlightAware.
Delta Air Lines said in a Sunday statement that "winter weather in portions of the U.S. and the omicron variant continued to impact Delta's holiday weekend flight schedule."
Delta said that of the airline's 4,155 flights on Sunday, 161 had been canceled and 40 more cancellations were expected. "Delta expects that around 40 flights may be canceled Monday," the airline said.
For the previous two days, Delta said over 500 flights were canceled because of the spread of Omicron, which has now been detected in every U.S. state.
Other airlines, such as United, American and JetBlue, were forced to cancel flights because of the rise in Omicron cases among staff.
An United Airlines spokesperson told Newsweek that among the 4,000 flights scheduled for Monday, 115 were canceled "due to Omicron staffing issues."
"The nationwide spike in Omicron cases has had a direct impact on our flight crews and the people who run our operation," the spokesperson continued. "As a result, we've unfortunately had to cancel some flights and are notifying impacted customers in advance of them coming to the airport. We're sorry for the disruption and are working hard to rebook as many people as possible and get them on their way during the holidays."
A spokesperson for JetBlue told Newsweek that the airline canceled 66 Monday flights because of staffing problems
In a statement, the spokesperson said, "Like many businesses and organizations, we have seen an increasing number of sick calls from Omicron. We entered the holiday season with the highest staffing levels we've had since the pandemic began and are using all resources available to us to cover our staffing needs.
"Despite our best efforts, we've had to cancel a number of flights, and additional flight cancellations and other delays remain a possibility as we see more Omicron community spread," the JetBlue spokesperson said.
An American Airlines spokesperson told Newsweek that "a number of COVID-related sick calls led us to make the difficult decision to precancel some flights scheduled for today."
The statement continued, "We proactively notified affected customers yesterday and are working hard to rebook them quickly. We never want to disappoint our customers and apologize for any disruptions to their holiday travel plans."
CNBC obtained a message to United Airlines pilots sent by Bryan Quigley, the senior vice president of flight operations, which said, "Our current pilot Covid-19 case count is on the rise."
If a flight has been canceled or delayed, passengers can get a refund, according to the federal Department of Transportation. "A passenger is entitled to a refund if the airline cancelled a flight, regardless of the reason, and the passenger chooses not to travel," the DOT says on its website.
For a flight that has been delayed, the DOT says, "many factors" can entitle a passenger to a refund, "including the length of the delay, the length of the flight, and your particular circumstances. DOT determines whether you are entitled to a refund following a significant delay on a case-by-case basis."
Airline passengers can use the DOT's website to file for a refund.
