Weather in Boston in September
September in Boston is warm outdoor weather. Days are long enough to be useful. Shade starts to matter at midday.
In United States, this is how Boston actually wears September, not how a country centroid would. Compared with July and January, September sits in the middle of Boston's year.
- Average temp
- 19°C
15–23°C
- Rainfall
- 90 mm
Showers likely
- Sunshine
- 7.1 h
hours per day
- Wind
- 16 km/h
What to expect
Daytime
Warm days in Boston in September. A hat starts to earn its keep at midday. Evenings are the comfortable part of the clock.
You can walk at more hours than in the fierce months. Still build in a pause when the sun is high. Nights are easy.
Rain
Mixed skies in Boston in September. Dry days and wet days share the month. Outdoor plans need a backup, not a cancellation policy.
Pack a shell you will actually carry. The monthly table is the place for totals. This is the feel: usable, interrupted.
Evening
Evenings are cooler. A layer helps after sunset.
What to pack
Sun protection
Rain jacket
A layer for cooler evenings
Where to stay in Boston
Dates are a starting point for September.
Travel guides for Boston
What to read before you book.
Average weather in Boston
TemperatureRainfall
Similar weather in September
Other destinations whose September averages sit close to this one.
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FAQs about Boston
Climate averages for Boston, 1991–2020.
The best time to visit Boston is between May and October, the most comfortable stretch of the year on these averages.
July is the hottest month, with an average around 24°C.
December is the wettest month, with about 107 mm of rain.
No. These are 1991–2020 climate normals from Meteostat, not a live forecast. Actual weather in any given week can differ.
