Indianapolis · August
Run in the morning.
Comfortable average high of 83°F, dipping to 66°F at night. Expect 16 rain days — plan around the radar. Humidity rises with the sun — morning runs catch the driest, coolest window.
Avg high / low
83° / 66°F
Humidity
72%
Rain days
16/mo
Wind
9 mph
What August feels like in Indianapolis
Sunrise
06:57
Mid-month average
Sunset
20:38
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 Indianapolis in August
The kit for August in Indianapolis: shorts and a short-sleeve are the standard kit, a water-resistant cap or jacket on standby.
August vs the surrounding months
vs July
-1° avg high
0 rain days
Indianapolis in July →
August
83°F avg high
16 rain days
Best: morning
vs September
+5° avg high
+5 rain days
Indianapolis in September →
Frequently Asked Questions
What is the best time of day to run in Indianapolis in August?+
Morning. Humidity rises with the sun — morning runs catch the driest, coolest window.
What's the average temperature in Indianapolis in August?+
Average high 83°F, average low 66°F.
How does August compare to surrounding months in Indianapolis?+
Compared to July (avg high 84°F), August is cooler. Compared to September (avg high 78°F), August is warmer.
Does it rain often in Indianapolis in August?+
Expect about 16 measurable rain days in August, on average.