The US Postal Service is suspending mail delivery in more than 100 ZIP codes because of the extreme cold

ANGELA WEISS/AFP/Getty Images

A mail delivery person pulls her cart through the snow in Brooklyn, New York.

• The United States Postal Service is suspending mail delivery in multiple states on Wednesday due to frigid temperatures, it said.
• About 100 zip codes in Michigan, Illinois, Nebraska, and more states will miss their regular delivery on Wednesday.
• There's no word yet on when deliveries might resume.

The United States Postal Service will suspend some mail deliveries due to extreme cold from a polar vortex that has swept across much of the country, sending temperatures plunging well into the negatives.

"Weather forecasters are warning of dangerously cold conditions in parts of the nation," the agency said in a press release Tuesday night.

"Some places could see wind chill readings as low as 60 below zero. Due to this arctic outbreak and concerns for the safety of USPS employees, the Postal Service is suspending delivery Jan. 30 in the following 3-digit ZIP Code locations.

• Michigan: 486-491, 493-499
• Indiana: 460-469, 472-475, 478, 479
• Chicago: 606-608
• Lakeland: 530-532, 534, 535, 537-539, 541-545, 549, 600, 602, 601, 611
• Detroit: 480-485, 492
• Central Illinois: 601, 603 - 605, 609, 613, 614, 616, 617
• Northern Ohio (Cleveland and Lima areas): 441, 458
• Ohio Valley (Cincinnati and Columbus areas): 452, 430-432
• Western Pennsylvania: (Erie and Bradford areas): 165, 169-177, 188
• Northland: 540, 546-548, 550, 551, 553-564, 566
• Hawkeye: 500-514, 520-528, 612
• Dakotas: 580-588, 570-577
• Eastern Nebraska: 680-689

Temperatures in Chicago Wednesday morning were around 20 degrees below zero, according to the National Weather Service, with wind chills extending even more into the negatives. The agency has warned that the frigid wind can cause hypothermia and frostbite in just a matter of minutes.

"It's cold, period," the NWS said. "Rarely do we see air temperatures into the -20s and they are area wide this morning, and rarely do we see wind chills colder than -45° but here they are."

On Tuesday, more than 1,500 flights were canceled in Chicago and other affected airports due to weather - and Wednesday isn't looking any better, with 2,461 cancellations nationwide as of 8:45 a.m., according to Flight Aware.