Forecasters are predicting that many parts of the United States could experience their lowest temperatures in two decades. Authorities have urged people to stay inside and stock up on food.
Weather analysts said the northern US plains, including North and South Dakota, the Great Lakes region and Ohio Valley, can expect an Arctic outbreak that has not been experienced in the region since 1994.
Chicago may face temperatures of around minus 10 degrees Fahrenheit (minus 23 degrees Celsius) on Monday, and that wind chill could make the air feel as cold as minus 50 to minus 60 degrees Fahrenheit (-45 to -51 degrees Celsius) in sections of north-central states.
Forecasters warned that exposed skin would suffer frostbite in as little as five minutes in such conditions.
People in the worst-hit areas have been urged to stay at home and ensure they have medical supplies and food.
In the state of Minnesota, schools will remain closed on Monday. Governor Mark Dayton said the closure was "to protect all our children from the dangerously cold temperatures."
It is the first time in 17 years that all schools will be closed in the state because of bad weather conditions.
The outbreak of freezing weather comes on the heels of a huge weather system that hit the US Midwest and Northeast in the first days of the new year. At least 16 people have died from storm-related causes.
Thousands of domestic and international flights have been canceled or delayed in several US cities.
tj/bk (AFP, Reuters, AP)