Right, it gets humid, but averages low ~80's. I'd honestly say its low ~70's, but this summer has been hot. I remember times when I was a child where it would still be snowing in May. Spring is also short, winter starts in October. I don't remember ever going out for Halloween without wearing a jacket, or where there wasn't cold rain or snow.
Michigan summers are much much milder (and shorter) than Texas summers (I lived in Houston for a few years).