In Photos: Deep Freeze Across The U.S.

The waterfalls at Falls Park sit frozen with just a trickle of water flowing underneath, Sunday, Jan. 5, 2014, in Sioux Falls, S.D. The city and surrounding areas were under a wind chill advisory Sunday afternoon with wind chills levels expected to dip as low as 55 degrees below zero. (AP Photo/Dirk Lammers)

On Sunday, the National Weather Service posted an advisory on its website saying:

“The coldest temperatures in almost two decades will spread into the northern and central U.S. today behind an arctic cold front.”
“Combined with gusty winds, these temperatures will result in life-threatening wind chill values as low as 60 degrees below zero (Fahrenheit/ -51 Celsius).”

Experts warned that in the weather that cold, frostbite can set in on uncovered skin in a matter of minutes.

Please click the photos for larger images:

Green Bay is seen frozen from the Cofrin Memorial Arboretum on the University of Wisconsin Green Bay campus Sunday, Jan. 5, 2014, in Green Bay. Temperatures not seen in years are likely to set records in the coming days across the U.S. Midwest, Northeast and South, creating dangerous travel conditions and prompting church and school closures. (AP Photo/Kiichiro Sato)

The waterfalls at Falls Park sit frozen with just a trickle of water flowing underneath, Sunday, Jan. 5, 2014, in Sioux Falls, S.D. The city and surrounding areas were under a wind chill advisory Sunday afternoon with wind chills levels expected to dip as low as 55 degrees below zero. (AP Photo/Dirk Lammers)

A Crestwood motorist tries to get his car moving along Watson Road in St. Louis as heavy snow falls on Sunday, Jan. 5, 2014. Snow-covered roads, high winds and ice were creating dangerous driving conditions from Missouri to Delaware on Sunday ahead of a “polar vortex” that’ll bring below-zero temperatures not seen in years to much of the nation in the coming days, likely setting records. (AP Photo/St. Louis Post-Dispatch, Robert Cohen)

A garden gnome sits up to its chin in snow Sunday, Jan. 5, 2014, in St. Louis. Snow that began in parts of Missouri Saturday night picked up intensity after dawn Sunday with several inches of snow on the ground by midmorning and more on the way. (AP Photo/Jeff Roberson)