Yeah, it's crazy. My inlaws live in Northern PA, I'm southern pa, and the difference is crazy. I'm also on the border of a metropolitan area, which doesn't help much. I'm also chalking some of the heat stress up to most of my flock being 7 weeks old or less, and about half of them are black or silkies, or both. Today the hens really started showing heat stress though, but tomorrow should be significantly cooler.
There's an article I just read about helping with heat, let me see if I can find it again.