A blizzard warning remains in effect from northeast Missouri into southeast Wisconsin and northeast Illinois, including the greater Chicago area.
The winter storm has led to hundreds of flight delays and cancellations, including several involving the Sioux Falls airport. You can check the latest delays at the airport's
The National Weather Service says heavy snow will continue through the early hours of Monday with up to a foot (30.48 centimeters) of snow expected in some areas and wind gusts of up to 50 mph (80.46 kph) likely to cause whiteout conditions. It also warned that downed tree limbs and power lines will continue to cause power outages.
Winter storm warnings and winter weather advisories are in effect from central Missouri into eastern Michigan.
The Chicago Department of Aviation says average departure delays at Chicago's O'Hare International Airport are 77 minutes and the flight-tracking website FlightAware reports that just over 350 flights headed to or from the U.S. were canceled as of early Monday.
(The Associated Press contributed to this report.)