September in Cambridge averages a daily high of 23.1°C with nights around 14.9°C. Expect roughly 8.8 wet days totalling 87.1mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Cambridge is May–September.
Based on BOSTON LOGAN INTERNATIONAL AIRPORT, MA US (8km), 1995–2024. 30 years of September data.