Boston Weather in September
23.7°C high · 12°C low · 91 mm rain · 6.4h sun
Sep is a warm month in Boston — not peak season, but a good time to avoid crowds.
September at a glance
| Metric | Value |
|---|---|
| Average high | 23.7°C |
| Average low | 12°C |
| Rainfall | 91 mm |
| Sunshine | 6.4 hours/day |
| Daylight | 12.3 hours |
What to pack in September
Pack comfortable clothes with a light layer for evenings, plus a raincoat and umbrella for Boston in September.
Boston weather by month
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Frequently asked questions
What is the weather in Boston in September?
Highs of 23.7°C and lows of 12°C, with about 91 mm of rain and 6.4 hours of sunshine per day.
Is September a good time to visit Boston?
Sep is a warm month in Boston — not peak season, but a good time to avoid crowds.
What to do in Boston · Best time to visit Boston
Climate data: Open-Meteo Historical (ERA5), 1991–2020. CC BY 4.0.