The scalding heat of summer can often pack a punch as soon as you step outside. And like a martial arts combo, a second strike often follows in quick succession: humidity. When humid weather rolls in, it leaves a heaviness in the Wisconsin summer air.

A long stretch of humid heat followed by intense thunderstorms is a weather pattern historically seen mostly in and around the tropics. But climate change is making humid heat waves and extreme storms more common in traditionally temperate midlatitude ...