Depending on where you live, fly-fishing for trout in August can be tough because water temperatures are usually at their highest points of the year. But there usually are places to find trout willing to eat a fly: small tributaries that often feature shade, cover, and cooler water. Feeder streams to trout rivers usually get ignored. They look too small to hold decent fish, or they look too tight for an overhead cast. But these tiny streams sometimes host large trout that leave the bigger waters because of high water temperatures or heavy boat traffic. Feeder streams always offer cooler water than main rivers, and food is not as abundant as on the big riffles of larger rivers. So you get trout that have not been educated, that eat all day long, and are eager to smash any fly that looks edible.