May in New Haven averages a daily high of 20.1°C with nights around 10.2°C. Expect roughly 12.5 wet days totalling 89.3mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit New Haven is May–June.
Based on NEW HAVEN TWEED AIRPORT, CT US (6.4km), 1995–2024. 23 years of May data.