Chicago Weather

Here's when peak heat, humidity are expected this week in the Chicago area

Prepare for temperatures to feel as hot as 115 degrees by Wednesday, the National Weather Service says

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It's about to get 'dangerously' hot, Chicago.

According to the National Weather Service, just one county in the Chicago area is Tuesday was under a heat advisory, with heat index values of 99 to 104 degrees expected. And beginning Wednesday at 11 a.m., all of northeastern Illinois will be under an excessive heat warning, with "dangerously hot conditions," and "heat index values of 110 to 115 expected."

Thursday, the area is under an excessive heat watch, though that could soon be upgraded to a warning as forecast models change, the NBC 5 Storm Team said.

But where exactly will the temperatures and heat indices be the highest, and at what times?

According to the NBC 5 Storm Team, heat and humidity is expected to peak Wednesday afternoon, between 1 and 4 p.m. A high temperature of 98 degrees Wednesday is likely, which would break the record of 97 degrees set in 1947, forecast models show.

MORE: How is the ‘heat index' calculated, and how do weather officials use it?

Additionally, the highest heat indices of between 110 and 115 degrees are likely to occur inland, the NWS said. Closer to the lake, heat indices are forecast to to be between 100 and 110 degrees.

Air temperatures will remain in the high 90s Thursday, and the area will be under an excessive heat watch, the NWS said. And although heat indices Thursday look to remain between 105 degrees and 110 degrees, the timing of when the heat could come to an end is not yet known, the NWS said.

For example, some models show widespread, high temperatures and humidity coming to an end late Thursday evening, according to the NWS. However, other forecasts show a "faster front," with cooler temperatures along the lake.

Additionally, some forecast models show thunderstorms could develop late Thursday into Friday, potentially disrupting the heat and keeping temperatures down, the NBC 5 Storm Team says.

The good news is the heat isn't expected to last long, as a cold front is expected to move in late Thursday night, bringing some relief by Friday.

High temperatures Friday are expected to sit in the 80s, dropping into the 70s by the weekend.

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