Chicago temperatures are expected to climb Monday after a round of morning thunderstorms, and the afternoon is expected to be hot and humid, particularly south of I-80.
Downtown Chicago will see temperatures in the mid-80s and a heat index in the high-80s, while further south in Cook County the heat index will reach all the way towards the mid and upper 90s, said National Weather Service meteorologist Scott Baker. Heat indices track how temperatures feel to the human body, taking humidity into account.
The city of Chicago announced Monday morning that cooling centers would be open for the day in order to provide residents with relief from the harsh weather. A full list of the dozens of air-conditioned cooling centers is available online.
“When the temperatures climb to extreme levels, we encourage everyone to monitor themselves and others for the telltale signs of heat-related illness,” wrote the Office of Emergency Management and Communications in a release on Monday morning. “Extreme sweating, intense thirst, nausea, fatigue or weakness, and dizziness or confusion can all be indicators of heat exhaustion or heat stroke.”
Chicago woke up to winds of up to 50 miles per hour and scattered storms that rolled through downtown Chicago early Monday on a path down toward northwest Indiana, Baker said. In addition to the strong winds, Baker said that the agency had received reports of hailstones one inch in diameter falling in both the Edgewater neighborhood and the northern suburb of Highland Park.
The National Weather Service issued a hazardous weather outlook warning for over a dozen counties in north and northeastern Illinois, including Cook County, at just before 5 a.m. Monday. The special weather statement regarding the storms’ path through the Chicago area expired at 8:30 a.m.
“We had a lot of showers and storms that developed over portions of Lake Michigan and then northern Illinois,” Baker said. “As that line continued to drop down to the southeast, it increased in coverage across the Chicago metro region and passed through downtown Chicago.”
The strong winds and heavy rainfall led the Federal Aviation Administration to issue a ground stop for Chicago O’Hare International Airport at just after 6 a.m., preventing any flights bound for O’Hare from departing the runway.
By 8:30 a.m., the ground stop had been lifted; however, half an hour later, planes leaving O’Hare were still experiencing average departure delays of an hour.