Weather in Indianapolis in August 2025
- August is usually the hottest month of the year in Indianapolis;
Average weather
Average temperature in Indianapolis in August
The expected average maximum temperature in August is +29°C with a maximum of +34°C and a minimum of +12°C.
The average maximum temperature goes down 14% by the end of the month, compared with the beginning of the month, from +28°C to +25°C.
Is Indianapolis warm or cold in August?
Indianapolis is typically warm in August.
Maximum temperatures go up compared to the previous month from +29°C to +29°C. The minimum temperature also goes down from +20°C to +19°C.
It’s generally warm, but pack a long-sleeve shirt for evenings.
August is the hottest month in Indianapolis, here is the comparison with other months:
Climate in Indianapolis in August
| July | August | September | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +29°C | +29°C | +25°C | ||||
| Min. temperature | ||||||
| +10°C | +7°C | 0°C | ||||
| Max. temperature | ||||||
| +39°C | +37°C | +37°C | ||||
| Rainfall | ||||||
| 93 mm | 79 mm | 69 mm | ||||
| Wind | ||||||
| 2 m/s | 2 m/s | 2 m/s | ||||
| Humidity | ||||||
| 72% | 74% | 72% | ||||
| Air pressure | ||||||
| 1015 HPa | 1015 HPa | 1016 HPa | ||||
| Sunny days | ||||||
| 5 | 6 | 8 | ||||
| Cloudy days | ||||||
| 9 | 9 | 10 | ||||
| Rainy days | ||||||
| 15 | 13 | 10 | ||||
| Snowy days | ||||||
| 0 | 0 | 0 | ||||
August weather is still as good as in July. The temperature levels stay the same in the area of +29°C for average maximum temperature during the day. As August arrives, the amount of rainfall goes down. On average, the rainfall volume decreases from 93 mm to 79 mm. Humidity rises from 72% to 74%. The average wind speed doesn’t change much during August, staying around 2 m/s. The good news is there are likely to be more sunny days in August, from 5 to 6.
September brings much the same weather, it remains good.
Wind
The average wind speed is 3 m/s getting up to 5 m/s which is a light breeze; barely moving the tree leaves.
The average wind speed in Indianapolis is gradually increasing during August, going from 2 m/s to 4 m/s over the course of the month.
Rain
How was the weather last August in Indianapolis?
Climate Change over Years
The climate in Indianapolis in August has not changed much over the last 43 years.
The average temperature was the lowest in 1979 (+15°C) and the highest in 2012 (+19°C). The driest year was 1999 with only 656 mm of rainfall, and the wettest year was 2019 with 1833 mm.
FAQ
Is August a good time to visit Indianapolis?
Can you sunbathe in Indianapolis in August?
Is Indianapolis rainy in August?
Is it sunny in Indianapolis in August?
Other cities in USA
Monthly weather in Indianapolis
Source of the data
For this page, we’ve looked at the typical weather in Indianapolis, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.