I'm a few hours south of you and agree that the hot, humid summers here are awful for pain and inflammation. I'm relatively new to sultry IL summers and I am not a fan. Late summer is called "corn sweat" season by the natives. Cute name. Still awful weather. Our neighbor loves this weather and says it's like "being wrapped in a warm, wet blanket". Gross!
My husband's company relocated us here from Santa Fe, NM. The stable climate of NM without a lot of humidity was much better for my achin' joints.
How do you feel if its cooler but humid? That's yucky for me too. A damp cold seems to sink right into my bones.