Airlines have canceled thousands of flights in the US due to winter weather

(CNN) — Airlines were still recovering from severe storms that hit the eastern United States on Friday, and every state was under some form of weather-related warning.

As of Saturday afternoon, more than 1,200 flights had been canceled and 4,700 had been delayed in the United States. Data from FlightAware tracking site. While that's a significant improvement from Friday's nearly 2,300 cancellations and 9,000 delays, airports in the Midwest and Northeast continue to experience significant travel delays.

In Michigan, more than 140,000 customers are currently without power, with Detroit Metropolitan Wayne County Airport delaying 40% of its departing flights. New York's Buffalo Niagara International Airport has canceled 60% of its flights. Denver, Boston and Chicago airports are also experiencing delays. Approximately 550 flights in and out of Chicago O'Hare International Airport were delayed. Denver International Airport had the second highest number of cancellations as temperatures dropped dramatically Saturday night.

These flight delays add to an already difficult week for airlines and their passengers. Last week, the federal government ordered the grounding of Boeing 737 Max 9s, causing more than 200 United and Alaska Airlines flights to be canceled each day. The Federal Aviation Administration instituted the order on Jan. 5 after part of the fuselage blew off an Alaska Airlines flight with 177 people on board. Shortly after takeoff from Portland, the plane was flying at an altitude of 16,000 feet when the incident caused a gap in the side of the plane and ripped the headrests from the seats.

United and Alaska Airlines, the two largest US airlines that operate the Max 9, were among the airlines with the most flight cancellations, according to FlightAware. United topped the list Saturday with nearly 250 flight cancellations, nearly 10% of its fleet. Alaska Airlines experienced the fourth highest number of cancellations, with nearly 120 flights cancelled.

Both airlines said last week that they had canceled all flights on their Max 9 aircraft until mid-January.