Indianapolis · September
Run in the morning.
Comfortable average high of 78°F, dipping to 60°F at night. Comfortable conditions all day, but morning consistently delivers the best combination of cool air and clear skies.
Avg high / low
78° / 60°F
Humidity
70%
Rain days
10/mo
Wind
9 mph
What September feels like in Indianapolis
Sunrise
07:26
Mid-month average
Sunset
19:52
Mid-month average
Time-of-day breakdown
Morning
Steady cool air, low wind, and good light. The standard runner window in most months.
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 Indianapolis in September
The kit for September in Indianapolis: shorts and a short-sleeve are the standard kit.
September vs the surrounding months
vs August
-5° avg high
-5 rain days
Indianapolis in August →
September
78°F avg high
10 rain days
Best: morning
vs October
+13° avg high
-2 rain days
Indianapolis in October →
Frequently Asked Questions
What is the best time of day to run in Indianapolis in September?+
Morning. Comfortable conditions all day, but morning consistently delivers the best combination of cool air and clear skies.
What's the average temperature in Indianapolis in September?+
Average high 78°F, average low 60°F.
How does September compare to surrounding months in Indianapolis?+
Compared to August (avg high 83°F), September is cooler. Compared to October (avg high 66°F), September is warmer.
Does it rain often in Indianapolis in September?+
Expect about 10 measurable rain days in September, on average.