Boston Weather in September

With daytime temperatures of 24°C (75°F) and nighttime lows of 15°C (59°F), September in Boston brings high temperatures during the day. It is also the driest month of the year, with minimal rainfall.

Rainfall in Boston in September

Enjoy minimal rain interruptions this month. It's an excellent time for outdoor plans, from sports to festivals. The climate data from previous years indicates about 9 days of rain, averaging 79 mm (3.1 in) for the month. When it rains this month, it tends to come down fairly heavily. Showers can be substantial even if they don't last all day.

Temperature in Boston in September

Weather in Boston is at its excellent in September. Highs reach 24°C (75°F), while nights settle around 15°C (59°F). This kind of day-to-night contrast is typical for this time of year. With overnight lows of 15°C (59°F), evenings can feel noticeably cooler than the daytime. An extra layer is a good idea, though the cool air makes for a good night's sleep.

Sunshine in Boston in September

With approximately 238 hours of sunshine, the days are filled with clear skies. It makes it a perfect month for being outside.

Wind Speed in Boston in September

Wind speeds average 5 m/s (10 knots) during September. At this speed, gentle to moderate breezes make small trees sway and the wind creates whitecaps on water bodies. Daily variations range from moderate winds to stronger breezes, creating excellent conditions for sailing, kite flying and wind sports.

Average water temperature in September

With water at 18°C (64°F), swimming is comfortable for most people. It feels refreshing rather than cold, though it depends a bit on personal preference.

Our weather planner can help you find worldwide destinations with pleasant weather during this period. August and September typically offer the best weather for Boston.