While July is typically a lousy month for fly fishing, there are ways to still get out on the water with the fly rod even while most trout streams get too warm. I actually like fishing in July because it is a great month for chasing smallmouths. They do well in the warm weather, and it is a great time for wet wading, making for a comfortable outing.
Smallmouths in July are keyed in to crayfish. Small crayfish start hatching out in June, and the creek is usually full of the little ones. Smallmouths feed heavily on them, and at times will key in on them and not hit much of anything else.
While the food is plentiful for the bass, they can get a little tricky if the weather gets really hot. If they absolutely refuse to feed on the surface during the hot weather, I switch to crayfish patterns and fish them under an indicator. Basically cast out, drag the indicator a foot or so closer, then let the fly drift downstream a couple of feet. I use this basic retrieve to cover the whole pool I am fishing, and it works really well in the heat.
So if your favorite trout stream is out of commission due to high temperatures, wadeable smallmouth streams are a great alternative and the fishing in them will hold up even in the summer heat.