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AirHistory

San Francisco, California vs Denver, Colorado Air Quality

Side-by-side air quality comparison using 10 years of EPA monitoring data. San Francisco, California has the edge with an Air Quality Grade of B (70/100).

MetricSan Francisco, CaliforniaDenver, Colorado
Air Quality GradeB (70/100)C (52/100)
Current Median AQI32 (Good)54 (Moderate)
5-Year Average AQI3854
10-Year Trend Improving (-7) Stable (+1)
Unhealthy Days/Year214
Primary PollutantFine Particulate Matter (PM2.5)Fine Particulate Matter (PM2.5)

Analysis

San Francisco, California outperforms Denver, Colorado on overall air quality. With a Grade B (70/100) and a median AQI of 32,San Francisco, California is currently in the "Good" range and is improving over the past decade.

Frequently Asked Questions

San Francisco, California has better air quality with a Grade B (70/100) compared to Denver, Colorado's Grade C (52/100). San Francisco, California has a current median AQI of 32 and is improving over the past decade.

San Francisco, California averages 2 unhealthy air days per year (5-year average), while Denver, Colorado averages 14. Unhealthy days are those when AQI exceeds 100 and sensitive groups should limit outdoor activity.

San Francisco, California's primary pollutant is Fine Particulate Matter (PM2.5), while Denver, Colorado's is Fine Particulate Matter (PM2.5). Both cities share the same dominant pollutant.

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