The polar vortex 2014 is creating life-threatening wind chills of as low as -70 degrees Fahrenheit along some portions of the Midwest, and places as far south as Atlanta find themselves in the single digits.
Several states have declared school closings for Monday, and possibly Tuesday as meteorologists predict an even colder morning tomorrow.
What exactly is a polar vortex?
A Polar vortex is a North Pole phenomenon that occurs seasonally. Its formation resembles that of a hurricane with fast-moving winds building up around an "eye".
However, as opposed to hurricanes which bring tropical storms to areas in the southern US, a polar vortex circles the Arctic at over 100 mph.
The weather phenomenon has been described as an arctic cyclone spinning freezing winds at the North and South Poles.
Then why is everyone making a big deal about the polar vortex 2014?
It is unusual for this mass of cold air to move as far south as the mainland United States as it is normally contained in the Canadian Northeast. Experts estimate that around 140 million people will be affected by the polar vortex 2014.
As an example, the last time Wisconsin saw temperatures this low was in February of 1996, when wind chills reached around -80 degrees Fahrenheit.
This time around, meteorologists expect Chicago to reach approximately -42 degrees Fahrenheit on Monday night, making frost bite possible in as little as five minutes on exposed skin.
The National Weather Service predicts by Tuesday, the polar vortex will affect 48 states, encompassing an area of 1.5 million square miles, with some areas experiencing below zero wind chills.
"Think of this as a polar hurricane," said NBC News meteorologist Al Roker of the polar vortex.
So, the polar vortex 2014 is making life miserable in large areas of the country. Chicago saw 11 inches of snow on Sunday, making it downright dangerous to be outside shoveling.
In Indianapolis, Indiana, Mayor Greg Ballard has changed the city's travel emergency level to "red", making it illegal for anyone to drive except for emergencies or to seek shelter, something that hasn't been done since 1978.
Missouri announced it was too cold for salt to be effective on streets, and some roads in Illinois were closed due to blowing and drifting snow.
The polar vortex 2014 continues its brutal march toward the Northeastern US, which will see temperatures plummet within the next 24-hours.
It is expected that the polar vortex 2014 will start to ease its firm grip on the US by mid-week. How cold is it where you are?