We’ve reached that stage of winter when there’s so much snow and the temperatures are so low that it’s pretty difficult to remember what summer felt like. The United States is in the midst of a polar vortex — a weather system bringing bone-chilling temperatures to many parts of the country. In much of the Midwest, particularly Illinois, Michigan, and Wisconsin, subzero temperatures have forced hundreds of school closures, and caused governors to declare emergencies. The high temperature in Des Moines, Iowa today will be minus 10 degrees, while the average winter high at Antarctica’s McMurdo Station is generally a balmy minus 6.

Many states are under chill warnings or advisories, as it’s possible to get frostbite in as little as five minutes without proper skin-covering clothing. In Minneapolis-St. Paul, for example, the wind chill is expected to be as low as minus 45 to minus 65 until Thursday morning.

And if you thought cold weather wasn’t enough to cause flight cancellations, think again. On Monday, 1,986 flights were canceled across the country due to the frigid weather, including a whopping 1,400 that were supposed to fly in or out of Chicago. According to CNN, “Amtrak also canceled all service to and from Chicago on Wednesday due to weather.”

Since falling temperatures have forced several universities across the Midwest to cancel classes this week, the only people happy about the polar vortex may be college students.

H/T: The New York Times