May in Hamilton averages a daily high of 24.4°C with nights around 11.4°C. Expect roughly 14.5 wet days totalling 109.3mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Hamilton is September–October.
Based on HAMILTON BUTLER CO REGIONAL AIRPORT, OH US (5.5km), 1995–2024. 27 years of May data.