By Kathy Orr

PHILADELPHIA (CBS) — Blame it on the Polar Vortex. A large pool of frigid air that governs the north pole during the winter.

READ MORE: All Employees Accounted For After Possible Tornado Hits Bensalem Car Dealership, Official Says

The Polar Vortex has dropped unusually far south, keeping the Contiguous United States below freezing overnight, and 90-percent of the country below freezing Tuesday!

Temperatures in Philadelphia will bottom out in the single digits by daybreak. Daytime temperatures will struggle to get into the low teens Tuesday afternoon.

Dangerous wind chills are expected through Tuesday. Sustained winds of 20-25 mph with gusts to 40 mph will bring wind chill values down to -10 to -15 degrees by Tuesday morning and will remain below zero through the day.  Wind chill values in the Lehigh Valley & Poconos could reach -20 to -30 degrees Tuesday morning.

WATCH: Extreme Temps Freeze T-Shirt In Seconds!

READ MORE: 76ers Take Tennessee Guard Jaden Springer With 28th Pick Of Draft

With temperatures dropping into the single digits Tuesday, some record lows will be challenged or broken. Here are some record lows for Tuesday:

Allentown: -4 (1942)
Atlantic City: 4 (1884)
Mt. Pocono: -5 (1988)
Philadelphia: 7 (1988)
Reading: 6 (1998)
Trenton: 6 (1912)
Wilmington: 10 (1988)

This won’t be a long lasting polar outbreak since the weather pattern remains progressive. Temperatures will be back in the 20s on Wednesday, 30s on Thursday and around 50 by the weekend.

Stay Warm, Stay Safe!

MORE NEWS: CBS3 Mysteries: Who Gunned Down 'Nice Guy' Civil Attorney Eric Birnbaum In Law Firm's Parking Lot?

Kathy Orr