August in Indianapolis averages a daily high of 29.2°C with nights around 18.7°C. Expect roughly 8.3 wet days totalling 79.3mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Indianapolis is September–October.
Based on INDIANAPOLIS INTERNATIONAL AIRPORT, IN US (12.5km), 1995–2024. 30 years of August data.