Boston (MA)
September
Weather in Boston, Massachusetts for September 2026
Your guide to Boston weather in September - trends and predictions
Until now, September 2026 in Boston is slightly cooler than the historical average by 0.6 °F.
Expect cooler weather in the next days in Boston with the forecast suggesting a temperature of 22.2 °F, lower than the historical average.
In general, the average temperature in Boston at the beginning of September is 24.1 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 20.3 °F by the end of September.
Boston experiences moderate rainfall in September, with an average of 8 rainy days and a total precipitation of 150.3 mm.
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Temperatures
Rain 🌧️
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22
Dry days
8
Rainy days
0
Snow days
22°/15°
Temperatures
15 km/h
Avg max wind
73 %
Avg humidity
Boston Weather September
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Temperatures trend during September in Boston
See the weather trend as well as the moving average line
September weather in Boston day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Sunny | 23° /16° | 32.1 mm | 5 | |
| Sept. 2 |  Overcast | 23° /14° | 7.7 mm | 5 | |
| Sept. 3 |  Partly cloudy | 25° /14° | 1.8 mm | 6 | |
| Sept. 4 | Sunny | 26° /15° | 0 mm | 6 | |
| Sept. 5 | Sunny | 24° /15° | 5.1 mm | 6 | |
| Sept. 6 | Overcast | 23° /17° | 13.6 mm | 5 | |
| Sept. 7 | Partly cloudy | 25° /14° | 6.2 mm | 6 | |
| Sept. 8 | Sunny | 26° /14° | 0.1 mm | 6 | |
| Sept. 9 | Sunny | 25° /16° | 7.1 mm | 5 | |
| Sept. 10 | Sunny | 25° /16° | 3.4 mm | 6 | |
| Sept. 11 | Sunny | 25° /16° | 0 mm | 6 | |
| Sept. 12 | Sunny | 26° /15° | 0 mm | 6.2 | |
| Sept. 13 |  Mist | 22° /17° | 13 mm | 1.9 | |
| Sept. 14 | Sunny | 24° /17° | 0 mm | 5.7 | |
| Sept. 15 | Sunny | 23° /15° | 0 mm | 6 | |
| Sept. 16 | Sunny | 29° /17° | 0 mm | 7 | |
| Sept. 17 | Overcast | 29° /19° | 4.9 mm | 6 | |
| Sept. 18 |  Light rain shower | 21° /14° | 28.2 mm | 5 | |
| Sept. 19 | Sunny | 20° /13° | 0 mm | 5 | |
| Sept. 20 | Overcast | 19° /14° | 0 mm | 5 | |
| Sept. 21 | Overcast | 19° /14° | 0 mm | 4 | |
| Sept. 22 | Light rain shower | 16° /14° | 36.6 mm | 3 | |
| Sept. 23 | Light rain shower | 15° /12° | 20.2 mm | 4 | |
| Sept. 24 | Sunny | 23° /12° | 0 mm | 6 | |
| Sept. 25 | Patchy rain possible | 20° /13° | 8.9 mm | 5 | |
| Sept. 26 |  Moderate or heavy rain shower | 21° /14° | 28 mm | 5 | |
| Sept. 27 | Overcast | 22° /13° | 4.9 mm | 5 | |
| Sept. 28 | Fog | 20° /13° | 2.9 mm | 4 | |
| Sept. 29 |  Cloudy | 19° /13° | 0 mm | 5 | |
| Sept. 30 | Overcast | 17° /11° | 0.1 mm | 4 | |
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Important Notice
Our weather forecast for Boston in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Boston forecast closer to your planned date for the most up-to-date weather information.
Change Month
Boston in September - FAQ
What are the expected maximum and minimum temperatures in Boston during September?
During September, expect a variety of temperatures with highs around 22° and lows near 15°, suitable for diverse activities and preferences.
How much rainfall should be expected in Boston during September?
Significant rainfall exceeding 150.3 mm is expected in Boston during September, occurring over more than 8 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Boston during September?
The average wind speed in Boston during September is 15 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Boston
Explore the daily rainfall trends and prepare for Bostons September weather 💧
Typically, Boston has 8 rainy days in September with a total of 150.3 mm of rainfall.
UV exposure in Boston during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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