Weather officials are forecasting hot, humid and stormy conditions this week, with the highest temperatures expected to reach the high 80s and low 90s Thursday and Friday.
Clusters of thunderstorms and resulting cooling air are possible during these hot days, which may lessen the heat. Wednesday will have the highest chance of storms in the Chicago area, but Kevin Doom, meteorologist with the National Weather Service, said it’s hard to tell how much that will cool temperatures.
“It’s just one of those situations where we might not have a great answer until we kind of see the whites of its eyes,” Doom said. “We’re just kind of keeping an eye on how things evolve upstream, but right now we are still expecting some pretty darn hot weather (on Wednesday).”
According to the National Weather Service, the heat index — what the temperature feels like to the human body — could reach up to 105 degrees by each afternoon Wednesday, Thursday and Friday. Doom said the higher heat indexes are likely for areas outside downtown Chicago and the lakefront, where it’ll feel “true to what the thermometer is saying.”
Heat indexes meeting or exceeding 103 degrees can lead to dangerous heat disorders with prolonged exposure and/or physical activity in the heat, according to the National Weather Service.
This week’s hot temperatures are remnants of the heat wave that affected the western United States last week, Doom said.
“That’s sort of shifting eastward a little bit, but luckily, as it does, it’s going to kind of fizzle away and so that’s why we’re not expecting temperatures quite as high,” he said.
Weather officials said this week’s temperatures will likely surpass Chicago’s hottest day on June 23, which was 93 degrees.
“The temperature isn’t really all that crazy high and we see these temperatures every summer. It’s just that the heat index is going to be quite a bit high,” Doom said.
On Monday evening, smoke from Canadian wildfires blanketed Chicago. The Illinois EPA issued an air quality alert for sensitive groups that expires Tuesday at midnight.
Children and adults with pulmonary or respiratory disease such as asthma should limit their time outdoors due to increased levels of PM2.5, a pollutant small enough to enter the bloodstream and lead to adverse health effects.
Midmorning conditions at Midway Airport were sunny and hazy at 74 degrees.
