CHICAGO (CBS) — Thursday is Sept. 1, the start of meteorological fall.

But don’t be fooled. You’ll be needing your air conditioner.

CBS 2 Meteorologist Megan Glaros says after a day with highs in the mid-80s and rising humidity on Wednesday, a warm front will lift to the northeast from central Missouri. That will pump up the heat to sweltering conditions reminiscent of July when Thursday comes around.

Areas to the south of Chicago, including Kankakee, can expect temperatures as high as the mid-90s, with sticky humidity. The forecast high for the area on Thursday is 93 degrees.

The heat will stick around on Friday, with highs of 94.

But afterward, a cold front will sweep in, bringing what could be a round of severe thunderstorms on Saturday.

As a result of that cold front, conditions will go from seeming reminiscent of mid-July to early October. On Sunday, the high is 75 with a low of 57, and for Labor Day on Monday, the forecast high is only 70 degrees, with a low of 54.