Passengers said they were confused about the large number of cancellations when skies were clear, and wondered why there were only four flights canceled at O'Hare International Airport, compared to the 82 flights canceled at Midway.
Southwest Airlines, the discount carrier that makes up over 90 percent of flights through Midway, proactively canceled dozens of flights due to extreme cold. The airline said the cold is slowing their operation as ground crews work to deice aircrafts.
The ABC7 Weather Team said the high was around 14 degrees for the Chicago area on Thursday, with the low around 7 degrees.
Southwest said they are reaching out to travelers on affected flights with updates on delays and information about new flights. Midway had 107 delayed flights by 3 p.m., and O'Hare had 323 delayed flights, according to Flight Aware.
Many Southwest travelers said they were frustrated after their flights were rebooked hours after their original departures.
"Nobody offered any answers...we were lucky we called right away, we were able to get another flight. It was really hectic earlier when we first got here," said Richard Meban, a Southwest passenger at Midway.
"I waited 70 minutes for them to call me back, but they did rebook me, so that was good...eight hours later than when I was originally scheduled to fly," said Stephanie Dupray, another Southwest passenger at Midway.
Midway advised travelers to confirm their flight status with their airline before heading out to the airport. Passengers can also get real-time flight information at flychicago.com.
Chicago's Department of Aviation said they are monitoring the situation closely.
WARMING CENTERS AVAILABLE ACROSS CITY FOR THOSE IN NEED
Chicago Catholic Charities crews were dispatched by the city Thursday to check on homeless people and offer to take them to warming centers.
"We are always concerned about our vulnerable population and our homeless residents," said Deputy Commissioner Joel Mitchell of the Family and Support Services Department.
Officials from several city departments gathered to discuss the resources available for residents during the bitter cold snap.
"Safety is the city's top priority, extreme weather is more than an inconvenience. It remains a serious and potentially life threatening event. We are asking everyone to keep exercising good judgement and remain indoors if at all possible," said Managing Director of the Office of Emergency Management and Communications Rich Guidice.
The cold weather is already responsible for four deaths so far this season in Cook County, according to officials. The latest death was on Tuesday on the city's West Side.
Since Christmas Day, 585 heating-related complaints have come into the Department of Buildings. The heat ordinance goes into effect each year from Sept. 15 to June 1.
"We are working toward inspecting all of those complaints. We also have the ability to work with the law department to get a case into court within 24 to 48 hours if we come across a situation with no heat, especially if there are children or seniors involved," said Commissioner Judy Frydland of the Buildings Department.
Watch the full forecast from the ABC7 Weather Team here: