AQI 42 · PM2.5 · Trend: Improving
| Average AQI | 42 |
| Good Days / Year | 245 |
| Unhealthy Days / Year | 5 |
| Primary Pollutant | PM2.5 |
| PM2.5 Average | 7.5 µg/m³ |
| Trend | ↓ Improving |
| Monitoring Stations | 28 |
| Nonattainment Areas | 0 |
Massachusetts benefits from strong environmental regulations, coastal air circulation, and a transition away from fossil fuels. Boston's dense transit use helps reduce vehicle emissions compared to similarly sized cities.
MassDEP Bureau of Air and Waste manages standards. Member of RGGI. Adopts California vehicle emission standards. Strong clean energy mandates.
No current nonattainment areas. Massachusetts has made significant improvements through coal plant closures and vehicle emission controls.