September in Pennsylvania marks a transition from summer’s heat to autumn’s cooler temperatures. Expect average highs ranging from the low 70s Fahrenheit (low 20s Celsius) in the northern parts of the state to the low 80s Fahrenheit (upper 20s Celsius) in the southern areas. Overnight lows typically fall into the 50s Fahrenheit (10-15 Celsius) statewide. This period experiences decreasing humidity and generally sunny days, though occasional rainfall is possible.
Understanding Pennsylvania’s climate during this month is crucial for various activities. The pleasant conditions make it ideal for outdoor pursuits such as hiking, biking, and exploring the state’s vibrant fall foliage as it begins to emerge. Farmers markets thrive with late-summer harvests, and many festivals and events take place, benefiting from the favorable weather. Historically, this time of year was important for preparing for the coming winter, a practice that continues to influence agricultural activities today.