Heat And Humidity Return To Chicago Before Chance Of Thunderstorms On Monday

CHICAGO — Hot and humid conditions returned to Chicago Sunday ahead of what is shaping up to be a stormy start to the week.

Chicagoans woke up Sunday morning to a departure from last week’s cooler conditions, with temperatures in the mid-80s and humidity levels raising the ‘feels like’ heat index into the 90s, according to the National Weather Service.

Heat indices are expected to peak around 100 degrees Monday, which is forecast to see a high temperature of 92 degrees.

The humidity spike will precede a series of thunderstorms that could hit the city as early as Sunday evening and last through Monday, National Weather Service eteorologist Rafal Ogorek said.

“The heat and humidity are creating conditions that are favorable for thunderstorms in the region,” he said. “It’s just a question of exactly where and when they will develop, and that’s still a little bit uncertain.”

Monday morning, from 6 a.m.-noon, will see the highest chance for storms with more wind and similar humidity levels to Sunday. Another round of storms could hit the area Monday night.

Most of the storm action will likely develop over Minnesota and Wisconsin before hitting Northern Illinois late Sunday or early Monday, Ogorek said. Exactly where and when they hit the area is still up in the air.

“We are thinking that storms should get going up far north in Minnesota and Wisconsin sometime later today, and they’ll eventually arrive in northern Illinois, sometime late overnight or tomorrow morning,” he said Sunday afternoon. “It’s entirely possible that the storms ended up passing to the east of the Rockford area, but it’s not not a certainty.”

Wednesday and Thursday will have highs in the mid-80s and less humidity.

Some residual wildfire smoke is still floating through the upper reaches of the atmosphere, and new smoke could blow into the city on Wednesday and Thursday, but won’t reach the same levels seen in previous weeks, he said.