May in Waterbury averages a daily high of 21.7°C with nights around 9°C. Expect roughly 12.9 wet days totalling 93.9mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Waterbury is August–October.
Based on MERIDEN MARKHAM MUNICIPAL AIRPORT, CT US (19.4km), 1995–2024. 24 years of May data.