September in Rhode Island typically marks a transition from summer to autumn. Expect gradually cooling temperatures, with average highs ranging 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 trend, dropping from the 60s Fahrenheit (high teens Celsius) to the 50s Fahrenheit (low teens Celsius). The state also experiences decreasing humidity levels, making the air feel crisper and more comfortable.
This period offers a pleasant blend of warm days and cool nights, ideal for outdoor activities like hiking, cycling, and exploring the state’s scenic coastline. The ocean waters retain summer’s warmth, extending the swimming season for some. Historically, September has been a popular time for tourism in Rhode Island, allowing visitors to enjoy the state’s natural beauty without the peak summer crowds. This transitional month also plays a crucial role in the local ecosystem, influencing the foliage’s change in color and preparing wildlife for the colder months.