AQI 50 · Ozone · Trend: Improving
| Average AQI | 50 |
| Good Days / Year | 210 |
| Unhealthy Days / Year | 10 |
| Primary Pollutant | Ozone |
| PM2.5 Average | 9 µg/m³ |
| Trend | ↓ Improving |
| Monitoring Stations | 12 |
| Nonattainment Areas | 1 |
The nation's capital has relatively moderate air quality for a major metro area. Dense public transit use helps, but heavy vehicle traffic and regional ozone transport during summer are persistent concerns.
DC DOEE (Dept. of Energy and Environment) sets among the strictest urban air quality standards. Vehicle inspection program, clean fleet requirements for government vehicles.
Washington DC-MD-VA — marginal ozone nonattainment as part of the broader metropolitan area.