What is the air quality in Seattle WA?

Seattle WA, United States of America has an annual US AQI of 43 (Reasonable) and average PM2.5 of 8 µg/m³, ranking #382 of 5856 cities. Main pollutant: PM2.5.

What is the cleanest month in Seattle WA?

June is typically the cleanest month (AQI 34) and October the most polluted (AQI 49).

Where does Seattle WA's air quality data come from?

PM2.5: 1998–2026 (monitors 1999–2026, satellite 1998; 2026 provisional (AirNow)). Measured by government monitoring stations. Full sources are on the methodology page.

Seattle WA, United States of America — Air Quality & Clean City Guide 2026

Seattle WA Air Quality Data

Global rank	City	Continent	AQI	PM2.5
382	Seattle WA, United States of America	North America	AQI 43	PM2.5 8 µg/m³