What is the air quality in San Francisco CA?

San Francisco CA, United States of America has an annual US AQI of 47 (Reasonable) and average PM2.5 of 9.4 µg/m³, ranking #585 of 5856 cities. Main pollutant: PM2.5.

What is the cleanest month in San Francisco CA?

March is typically the cleanest month (AQI 40) and January the most polluted (AQI 57).

Where does San Francisco CA's air quality data come from?

PM2.5: 1998–2024, 2026 (monitors 1999–2024, 2026, satellite 1998–2003, 2009, 2023; 2026 provisional (AirNow)). Measured by government monitoring stations. Full sources are on the methodology page.

San Francisco CA, United States of America — Air Quality & Clean City Guide 2026

San Francisco CA Air Quality Data

Global rank	City	Continent	AQI	PM2.5
585	San Francisco CA, United States of America	North America	AQI 47	PM2.5 9.4 µg/m³