Updated 2:20 p.m.
Record low temperatures continued for a second day in a row in Chicago on Thursday, the National Weather Service reported.
The low Thursday morning was 21 degrees below zero, making it the coldest Jan. 31st on record. The previous record, minus 12, was set on the same day in 1985.
On Wednesday, Chicago had a low of minus 23, breaking a record set in 1966 for coldest Jan. 30.
The weather service said that, in records dating back to the 1870s, Wednesday was the 14th coldest daily temperature in Chicago. Thursday is the 15th coldest.
An all-time record low was recorded Thursday in Rockford, about 90 miles northwest of Chicago. The mercury fell to minus 30 in the morning, breaking the all-time record set in 1982.
A slight warm-up was forecast in Chicago on Thursday, with a high temperature of minus one degree, but wind chills were still making it feel like 40 degrees below zero.
The intense cold continued to disrupt air travel, commuter train service and schools in Chicagoland on Thursday. More people were expected to return to work in the city, which resembled a ghost town Wednesday after many private and public employers shut down due to the record cold, or told people to work from home.
A new round of snowfall is on the way in the Chicago region starting this afternoon and continuing into the evening, the weather service said. Up to 4 inches could fall in some areas. The heaviest snowfall will be far west of the city.
Then an extraordinary temperature swing will begin this weekend, with highs in the 40s and light rain. The high temperature Monday could reach 47 degrees.
New IL record?
A new all-time record low temperature for Illinois may have been set Thursday in Mount Carroll. The National Weather Service says its weather observer in Mount Carroll, located about 130 miles west of Chicago, reported a low of minus 38 degrees Thursday morning. The weather service will review that report, and if it decides it's accurate, then it would be a new record low in Illinois, breaking minus 36 in Congerville in 1999.
Chicago Public Schools and hundreds of public and private schools across the city and suburbs were closed for a second day. Many colleges remain closed or will not reopen until later Thursday.
Metra is running on a reduced schedule Thursday after shutting down operations shortly before 11 p.m. Wednesday. The South Shore Line that runs between Chicago and northwest Indiana and the Metra Electric District line on the South Side and south suburbs were shut down Wednesday and will not resume operations until Friday.
CTA trains were running Thursday morning, but there were delays on the Blue, Purple, Red and Yellow lines due to signal problems.
More than 1,400 flights were canceled Thursday at O’Hare International Airport, the city’s department of aviation reported. There have been more than 250 cancellations at Midway airport. Both airports were seeing average flight delays of 15 minutes on Thursday.
The Chicago Department of Buildings is reminding landlords it’s their job to keep tenants safe during the dangerous cold.
"It’s your responsibility to keep the heat on in your building and have smoke and carbon monoxide detectors in your building," said department Commissioner Judy Frydland at a city news conference Wednesday night.
Frydland said her department is making emergency repairs to properties without adequate heat, and the department will go to court Friday to get reimbursed for repair costs. Chicago requires landlords to keep heat in buildings at a minimum of 68 degrees during the day and 66 at night. Residents with insufficient heat should call 311.
This is global warming?
The record low temperatures in Chicago and across the upper Midwest this week may perplex some people in an era of climate change blamed by many scientists on human activities that cause rising levels of carbon dioxide and other greenhouse gases.
But global warming doesn't mean that "winter has been cancelled," said Andrew Dessler, a professor of atmospheric sciences at Texas A&M University.
"It still is going to get cold in Chicago, you’re still occasionally going to get extreme cold events, and every once in a while you’ll set a record cold event," Dessler added. But he said those events are happening much less frequently and will continue to decline.
"And that’s climate change," Dessler said. "Eventually, one day, we will stop getting them, but we haven’t warmed the planet enough for that to happen yet."
Dessler said that, as the world gets warmer, there will be more extreme heat events. But whether increasing temperatures result in more extreme cold events is an area of active scientific debate.