September in Lynn averages a daily high of 23.1°C with nights around 13.3°C. Expect roughly 8 wet days totalling 85.3mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Lynn is June–September.
Based on MARBLEHEAD, MA US (7.9km), 1995–2024. 30 years of September data.