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The temperatures in Boston in September are comfortable with low of 15°C and and high up to 24°C.
You can expect about 3 to 8 days of rain in Boston during the month of September. It’s a good idea to bring along your umbrella so that you don’t get caught in poor weather.
Our weather forecast can give you a great sense of what weather to expect in Boston in September 2025.
If you’re planning to visit Boston in the near future, we highly recommend that you review the 14 day weather forecast for Boston before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 1° / -5° | 6 | 15 | 10 | 119 mm | Awful | Boston in January |
| February | 2° / -4° | 6 | 12 | 10 | 131 mm | Awful | Boston in February |
| March | 7° / 0° | 7 | 15 | 8 | 149 mm | Awful | Boston in March |
| April | 13° / 5° | 8 | 20 | 2 | 133 mm | Awful | Boston in April |
| May | 20° / 10° | 7 | 24 | 0 | 100 mm | Ok | Boston in May |
| June | 24° / 15° | 7 | 23 | 0 | 120 mm | Good | Boston in June |
| July | 28° / 19° | 7 | 24 | 0 | 119 mm | Good | Boston in July |
| August | 28° / 19° | 4 | 27 | 0 | 99 mm | Perfect | Boston in August |
| September | 24° / 15° | 4 | 26 | 0 | 79 mm | Perfect | Boston in September |
| October | 17° / 10° | 6 | 25 | 0 | 134 mm | Good | Boston in October |
| November | 10° / 4° | 6 | 22 | 2 | 111 mm | Bad | Boston in November |
| December | 5° / -1° | 7 | 17 | 7 | 143 mm | Awful | Boston in December |