Air Quality in Washington
Live AQI readings for 2 cities in Washington. Click any city for real-time pollution data, PM2.5 levels and personalised health guidance.
2 Cities in Washington
About Air Quality in Washington
Air quality in Washington is monitored by the US EPA AirNow network using certified government sensors. Data is updated hourly and reported using the US Air Quality Index (AQI) — a 0–500 scale where lower is better.
The AQI is calculated from six key pollutants: PM2.5, PM10, ground-level ozone, nitrogen dioxide, sulfur dioxide, and carbon monoxide. The dominant pollutant — whichever reads highest — sets the overall AQI for that city. Learn how AQI is calculated →