Boston Weather In September
Boston September Weather is definitely hotter in the beginning of the month than it is in the end of the month, with an average drop in temperature of about 5°F. Storms are always possible, but usually don't last very long.
You can experience some great weather days in Boston in September, with moderate temperatures and sunny days. Or you might hit a week of clouds, rain, and humidity. Always check the latest weather forecast when planning your day.