Indianapolis Air Quality in August
Across 2019–2025, Indianapolis's August air quality had a median AQI of 57 (Moderate) over 217 monitored days in the Indianapolis-Carmel-Anderson, IN area. 1.9% of August days (4 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 76.0% of days. The cleanest August on record here was 2020 (median AQI 53, 0 days above 100) and the worst was 2023 (median 60, 2 days above 100, peak AQI 151).
- Good: 23.0%
- Moderate: 75.1%
- Unhealthy for Sensitive Groups: 1.4%
- Unhealthy or worse: 0.5%
Extra Protection for Indianapolis Homes
Air quality in Indianapolis is moderate (AQI 55), with fine particles (PM2.5) the main concern. A True-HEPA purifier gives sensitive groups — kids, seniors and anyone with asthma or allergies — cleaner air indoors on days like today.
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How is the air in Indianapolis in August?
Moderate on a typical day: median AQI 57 across 2019–2025, with 1.9% of August days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓23.0% of August days were Good (AQI 0–50), 75.1% Moderate (51–100).
- ✓4 days of 217 reached AQI 101+; the August peak was 151.
- ✓Best August: 2020; worst August: 2023.
Frequently asked questions
What is the air quality like in Indianapolis in August?▾
Across 2019–2025, the median daily AQI in Indianapolis in August was 57 (Moderate). 23.0% of days were Good, 75.1% Moderate, and 1.9% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is August a good time for outdoor exercise in Indianapolis?▾
A typical August day in Indianapolis is Moderate (median AQI 57): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 53 of August days (1.9%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Indianapolis's August air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 76.0% of August days in Indianapolis. The highest August AQI recorded in 2019–2025 was 151 (Unhealthy), in 2023.
Indianapolis August air quality, year by year
Indianapolis August air quality by year (Indianapolis-Carmel-Anderson, IN, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 57 | 1 | 112 | PM2.5 |
| 2020cleanest | 31 | 53 | 0 | 84 | PM2.5 |
| 2021 | 31 | 60 | 1 | 106 | PM2.5 |
| 2022 | 31 | 54 | 0 | 73 | PM2.5 |
| 2023worst | 31 | 60 | 2 | 151 | PM2.5 |
| 2024 | 31 | 58 | 0 | 100 | PM2.5 |
| 2025 | 31 | 55 | 0 | 100 | PM2.5 |
What August air means in Indianapolis
A typical August day in Indianapolis is Moderate (median AQI 57): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 53 of August days (1.9%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
August's median AQI of 57 is in line with Indianapolis's whole-year median of 56, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median August AQI across every EPA metro area (104,152 metro-days, 2019–2025) is 45, so Indianapolis runs above the national August norm; 1.9% of its August days topped AQI 100 versus 3.5% nationally (below average).
August is part of Indianapolis's summer season (June, July, August); the summer page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Indianapolis
The latest EPA AirNow observation puts Indianapolis's AQI at 55 (PM2.5). The figures above are multi-year month statistics, not today's reading.
View current Indianapolis air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Indianapolis-Carmel-Anderson, IN), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.