AQI 55 · PM2.5 · Trend: Improving
| Average AQI | 55 |
| Good Days / Year | 195 |
| Unhealthy Days / Year | 15 |
| Primary Pollutant | PM2.5 |
| PM2.5 Average | 9.8 µg/m³ |
| Trend | ↓ Improving |
| Monitoring Stations | 38 |
| Nonattainment Areas | 2 |
Indiana faces air quality challenges from its heavy reliance on coal power and concentrated steel industry in the northwest. Gary has some of the worst localized industrial air pollution in the Midwest. Indianapolis has moderate vehicle-driven pollution.
Indiana DEM (Dept. of Environmental Management) manages air quality. Lake County (Gary) has special monitoring due to steel industry emissions.
Gary/Lake County — PM2.5 nonattainment (US Steel). Indianapolis metro — marginal ozone nonattainment.