Boston typically experiences a transition from summer to autumn during September. Average high temperatures gradually decrease from the low 70s Fahrenheit (low 20s Celsius) at the beginning of the month to the mid-60s Fahrenheit (high teens Celsius) by the end. Overnight lows follow a similar pattern, moving from the upper 50s Fahrenheit (mid-teens Celsius) to the low 50s Fahrenheit (low teens Celsius). This period is known for its generally pleasant days, crisp nights, and decreasing humidity levels.
Understanding the typical climate conditions for this time of year is valuable for planning a variety of activities, from outdoor excursions and sightseeing to special events and festivals. Comfortable temperatures and lower humidity can create ideal conditions for exploring the city’s historical sites, parks, and waterfront areas. Historically, this month has offered a welcome respite from the summer’s heat and humidity while still providing ample opportunities for outdoor enjoyment before the arrival of colder weather.