Indianapolis Air Quality in 2025
In 2025, Indianapolis's air quality (Indianapolis-Carmel-Anderson, IN area) had a median daily AQI of 54 (Moderate) across 365 monitored days. 8 days (2.2%) reached Unhealthy for Sensitive Groups or worse, 137 were Good, and the year's peak AQI was 170 (Unhealthy). Fine particulate matter (PM2.5) set the daily AQI on 267 of those days. The cleanest month of 2025 was October (median AQI 42, 0 days above 100) and the worst was September (median 62, 4 days above 100, peak 122).
- Good: 37.5%
- Moderate: 60.3%
- Unhealthy for Sensitive Groups: 1.6%
- 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 was Indianapolis's air quality in 2025?
Moderate on a typical day: median AQI 54, with 8 days above AQI 100 out of 365 monitored — the 5th cleanest of 7 years on record for the area.
- ✓Peak AQI in 2025: 170 (Unhealthy).
- ✓Fine particulate matter (PM2.5) was the main pollutant on 267 days.
- ✓Cleanest month: October; worst: September.
Frequently asked questions
What was the average AQI in Indianapolis in 2025?▾
EPA's Air Quality System puts Indianapolis's (Indianapolis-Carmel-Anderson, IN) median daily AQI for 2025 at 54, which is Moderate. 8 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 170.
Which month had the worst air quality in Indianapolis in 2025?▾
The cleanest month of 2025 was October (median AQI 42, 0 days above 100) and the worst was September (median 62, 4 days above 100, peak 122).
Was 2025 a good or bad year for Indianapolis's air?▾
Among the 7 years EPA has published for the area (2019–2025), 2025 ranks 5th cleanest by days above AQI 100. 2025's median of 54 is in line with the area's typical annual median of 56.
Indianapolis month by month in 2025
Indianapolis air quality month by month, 2025 (Indianapolis-Carmel-Anderson, IN, EPA AQS daily AQI)
| Month | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| January | 31 | 47 | 0 | 86 | PM2.5 |
| February | 28 | 55 | 0 | 74 | PM2.5 |
| March | 31 | 52 | 0 | 87 | PM2.5 |
| April | 30 | 50 | 0 | 73 | PM2.5 |
| May | 31 | 45 | 0 | 80 | PM2.5 |
| June | 30 | 59 | 1 | 108 | PM2.5 |
| July | 31 | 58 | 2 | 170 | PM2.5 |
| August | 31 | 55 | 0 | 100 | PM2.5 |
| Septemberworst | 30 | 62 | 4 | 122 | PM2.5 |
| Octobercleanest | 31 | 42 | 0 | 80 | PM2.5 |
| November | 30 | 58 | 1 | 117 | PM2.5 |
| December | 31 | 57 | 0 | 82 | PM2.5 |
How 2025 compares
Among the 7 years EPA has published for the area (2019–2025), 2025 ranks 5th cleanest by days above AQI 100.
2025's median of 54 is in line with the area's typical annual median of 56.
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 annual 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.