Temperatures overnight sank into the negative double digits in nearly a dozen states, with the polar vortex descending on the Midwest and threatening to break all-time cold records.
The big picture: Mail deliveries have been suspended, schools and businesses closed, and Midwesterners warned that the frigid cold is not to be trifled with. Even so, some brave souls have ventured outside to test out the temperatures.
Mail delivery on Wednesday is suspended in several cities in the Midwest based on brutal cold temperatures, the U.S. Postal Service announced.
Details: Mail will not be delivered in parts of Minnesota, Michigan, Indiana, Illinois, Wisconsin, Ohio, Iowa, western Pennsylvania, the Dakotas and Nebraska. Schools, businesses and government services are closed, and hundreds of flights have been delayed or canceled throughout the country.
The polar vortex is making a painful visit to the Midwest beginning Tuesday. All-time cold temperature records will be set and wind chills will plummet to dangerous levels, with more than 83 million people expected to see temperatures drop below 0°F by week's end.
The big picture: A piece of the polar vortex has spun south, out of its typical home in the Arctic, for a life-threatening sojourn in the U.S. This is bringing ultra-cold weather to at least 15 states, where wind chill warnings and advisories have been issued as of Tuesday morning. Chicago could set a record for its coldest daily high temperature on record, with the high on Wednesday unlikely to edge past minus 15°F, beating the old record of minus 11°F set on Jan. 18, 1994.