See the Most Shocking Photos of the Polar Vortex Hitting the Midwest Right Now
This week, residents from the Midwest, the Dakotas and Western New York are experiencing some of the coldest temperatures to hit the region in more than two decades, according to The Weather Channel. Parts of Lake Michigan in Kenosha, Wisconsin, froze over on Wednesday morning.
A homeless man sits in the falling snow in the Financial District on New York City.
A man walks along an ice-covered break-wall in Chicago, Illinois.
So, what's a polar vortex, anyway? As NOAA describes, it is a large zone of low pressure and cold air at the Earth's poles. The air travels counter-clockwise (hence the "vortex"), but can occasionally be sent from the north pole down south.
The extreme weather can hinder travel plans around the country.
A ship breaks ice as it travels through the Chicago river.
A thermometer in Minneapolis, Minnesota, shows almost -30 degrees Fahrenheit.
Icicles form outside a bridal shop in Minneapolis, Minnesota.
Ice and snow build up along Lake Michigan in Chicago, Illinois.
These temperatures can also spark hypothermia, when a person’s internal temperature drops below 95 degrees. Seek help immediately if you or someone you know may have developed it.
A man tosses hot water into the cold air, which instantly solidifies and turns into snow. You'll likely see many people do this on social media this week.
Ice covers the Chicago River, as the weather causes business and schools to close, and thousands of flights to be canceled.
Ice and snow build up along Lake Michigan in Chicago, Illinois, on Tuesday.
Cold temperatures and extreme weather take over New York!
Mist builds along Chicago River in Illinois
Icicles hang from a gazebo in Central Park in New York City.