On the hottest days of the summer I like to go stand in the local river to cool off. And since there might be people looking, I bring my 3wt
I know that the only fish dumb enough to be out on a day like that are juvenile smallmouth of about 8". If there was any chance of bigger fish, I'd bring a bigger rod.
Besides, the little rod is a good size for that sort of fishing as catching 60-70 of the little rascals on a bigger rod tends to put a hurt on your shoulder