Flight Aware data showed 3,898 cancellations Saturday, with 8,822 more expected Sunday, and an additional 1,549 on Monday. More than 3,004 delays were also recorded Saturday, Anadolu Agency reported.
Millions across the US face states of emergency as the storm is expected to impact areas from the Southwest through the Northeast beginning Saturday.
The National Weather Service said heavy snowfall will hit from Oklahoma through southern Maine, while "widespread freezing rain and sleet" are forecast throughout the South and Southeast.
US President Donald Trump earlier warned that a "record cold wave" is expected to strike dozens of states. Trump approved emergency declarations for 12 states, as at least 22 states and Washington DC, declared states of emergency.