Philadelphia · September
Run in the morning.
Comfortable average high of 79°F, dipping to 62°F at night. Humidity rises with the sun — morning runs catch the driest, coolest window.
Avg high / low
79° / 62°F
Humidity
71%
Rain days
12/mo
Wind
10 mph
What September feels like in Philadelphia
Sunrise
06:42
Mid-month average
Sunset
19:08
Mid-month average
Time-of-day breakdown
Morning
Coolest, driest air of the day. The window before sunrise is the most reliable comfortable hour.
Midday
Mild but UV and traffic peak. Workable if you don't mind shifting your pace.
Evening
Warm and runnable. Crowded routes but the air's typically calm.
What to wear running in Philadelphia in September
The kit for September in Philadelphia: shorts and a short-sleeve are the standard kit, a water-resistant cap or jacket on standby.
September vs the surrounding months
vs August
-6° avg high
-3 rain days
Philadelphia in August →
September
79°F avg high
12 rain days
Best: morning
vs October
+12° avg high
-1 rain days
Philadelphia in October →
Frequently Asked Questions
What is the best time of day to run in Philadelphia in September?+
Morning. Humidity rises with the sun — morning runs catch the driest, coolest window.
What's the average temperature in Philadelphia in September?+
Average high 79°F, average low 62°F.
How does September compare to surrounding months in Philadelphia?+
Compared to August (avg high 85°F), September is cooler. Compared to October (avg high 67°F), September is warmer.
Does it rain often in Philadelphia in September?+
Expect about 12 measurable rain days in September, on average.