- The polar vortex swept parts of the US Midwest and East Coast this week, forcing millions of Americans to contend with subzero temperatures.
- The polar vortex is an area of circulating cold air that rings the planet's North and South poles. Sometimes that vortex destabilizes, sending surges of Arctic air south.
- Windchill temperatures were as cold as minus 60 degrees in Minnesota and minus 45 in Chicago Thursday, far below average for this time of year.
- So far, 21 deaths have been linked to the cold snap.
- If Arctic ice continues to melt, polar-vortex events could get more frequent.
For the first time since 2014, the polar vortex descended on North America.
More than 84 million Americans in the Midwest and parts of New England experienced subzero temperatures, CNN reported. Wind-chill advisories in the Midwest and Northeast impacted 140 million Americans.See the rest of the story at Business Insider
- The polar vortex striking the US will cause temperatures to plummet up to 40 degrees colder than normal
- How long you can stay in extremely cold temperatures before getting frostbite
- Scientists just drilled the deepest hole ever in western Antarctica, going 2 kilometers down through the ice to study how it's melting