September in Weymouth averages a daily high of 23.4°C with nights around 13.1°C. Expect roughly 9.6 wet days totalling 99.8mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Weymouth is May–September.
Based on HINGHAM, MA US (2.3km), 1995–2024. 30 years of September data.