(Photo by edward stojakovic)

The United States Postal Service said it would suspend mail delivery in some states on Jan. 30, 2019, because of extreme cold from a polar vortex in much of the country this week that has sent temperatures plunging well into negative degrees.

"Weather forecasters are warning of dangerously cold conditions in parts of the nation," the agency said in a press release on Jan. 29, 2019. "Some places could see wind chill readings as low as 60 below zero."


It added that "due to this arctic outbreak and concerns for the safety of USPS employees, the Postal Service is suspending delivery" on Jan. 30, 2019, in several three-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

It's unclear when deliveries will resume in those areas.

More than 220 million Americans will be forced to contend with below-freezing temperatures. The temperature in Chicago on Jan. 30, 2019, was about 20 degrees below zero, according to the National Weather Service, with the windchill extending even more into the negatives.

"It's cold, period," the NWS's Chicago office said, adding that it's rare to see temperatures in the -20s and windchill figures below -45.

In many places, it's simply too cold for people to be outside safely. The NWS, as well as other weather and medical officials, has warned that the frigid wind can cause hypothermia and frostbite in minutes.

"You're talking about frostbite and hypothermia issues very quickly, like in a matter of minutes, maybe seconds," Brian Hurley, a meteorologist with the Weather Prediction Center, told The Associated Press.

More than 1,500 flights were canceled in Chicago and other airports on Jan. 29, 2019, because of the weather — and Jan. 30, 2019, isn't looking any better, with 2,461 cancellations nationwide as of 8:45 a.m., according to FlightAware.

Schools were closed in Chicago and parts of eastern Iowa on Jan. 30, 2019, in addition to closures in Michigan, Wisconsin, and Minnesota.

This article originally appeared on Business Insider. Follow @BusinessInsider on Twitter.