May in Dorchester averages a daily high of 21°C with nights around 9.3°C. Expect roughly 12.4 wet days totalling 83mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Dorchester is May–June.
Based on JAMAICA PLAIN, MA US (4.1km), 1995–2024. 25 years of May data.