Total cancellations as of 2 p.m. ET within, into, or out of the United States stood at 1,034, with 2,694 flights delayed, marking the fifth day of flight cancellations.
Delta said it was working to reroute and substitute some planes.
U.S. carriers canceled more than 1,000 flights on Monday after grounding thousands of planes over the Christmas holiday weekend as airlines struggled with staff shortages from COVID-19 infections and bad weather in parts of the country.
Snowy weather in the Pacific Northwest on Monday contributed to the cancellation of more than 110 flights scheduled to land at Seattle-Tacoma Airport.
With rising infections causing pilots and cabin crew to quarantine, airlines have been forced to cancel many flights.
The average number of new COVID-19 cases in the United States has risen 55 percent to over 205,000 per day over the last seven days, according to a Reuters tally.
The spread of the Omicron variant of the coronavirus prompted the U.S. government’s top infectious disease expert to suggest on Monday the government consider mandating vaccines for travelers taking domestic flights.
The U.S. Centers for Disease Control and Prevention (CDC) said on Monday it was shortening the recommended isolation time for infected Americans to five days from 10 days previously, if they are asymptomatic. The move could help airlines and other businesses mitigate staff shortages.
By Kannaki Deka