I know what you're saying, but again you mentioned the Yough which is an option. As well as the Allegheny which is another tailwater, and then there's plenty of wild trout streams(of all 3 species). Yeah, even some of the wild trout streams get a little toasty too and it's best to leave them alone in the summer, but there are still a bunch of them that stay cold and fishable throughout the summer.
And you said late April through May, what about October through early-mid April?
And fwiw, I had good fishing(w/ good water temps) for stocked trout all the way until last week when I last fished for them. The temps are starting to get a little hairy on some creeks now though, but the wild trout streams and cold tailwaters will fish.
And then of course there's warmwater species, which brings us back on subject......carry on..