May in Cincinnati averages a daily high of 24.2°C with nights around 11.5°C. Expect roughly 13.7 wet days totalling 125.4mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Cincinnati is September–October.
Based on CINCINNATI MUNICIPAL AIRPORT LUNKEN FIELD, OH US (8.8km), 1995–2024. 30 years of May data.