Ohio EPA classifies it as Warmwater Habitat, managed as Warmwater Habitat — that is the season and creel row to look up. The Rocky River averages 75.8 °F in July across 1 gauged stretch, so the middle of summer is a morning-and-evening proposition rather than a bad month.
There is no hatch record for Ohio in this dataset, and the nearest one on file is the Virginia mountains' — too far from this water to stand in for it. So this page says what it can measure: the season and the water temperature.
Ohio publishes no season on this reach in the file this site reads. Ohio EPA classifies it as Warmwater Habitat, managed as Warmwater Habitat, and that is the row to look up in the digest — the season and creel rules follow the classification rather than the river. What the state designates on this water → Ohio regulations →
July is the warmest month and the one this site measures: 1 gauged stretch average 75.8 °F . Everything either side of July is colder than that.
Rocky River — live water temperature, regulations and access