September in Nashua averages a daily high of 24.1°C with nights around 10.6°C. Expect roughly 8.9 wet days totalling 102.3mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Nashua is May–June.
Based on NASHUA 2 NNW, NH US (2.9km), 1995–2024. 30 years of September data.