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AirHistory

Denver, Colorado vs Maricopa, Arizona Air Quality

Side-by-side air quality comparison using 10 years of EPA monitoring data. Denver, Colorado has the edge with an Air Quality Grade of C (52/100).

MetricDenver, ColoradoMaricopa, Arizona
Air Quality GradeC (52/100)F (9/100)
Current Median AQI54 (Moderate)72 (Moderate)
5-Year Average AQI5490
10-Year Trend Stable (+1) Worsening (+3)
Unhealthy Days/Year14126
Primary PollutantFine Particulate Matter (PM2.5)Ground-Level Ozone

Analysis

Denver, Colorado outperforms Maricopa, Arizona on overall air quality. With a Grade C (52/100) and a median AQI of 54,Denver, Colorado is currently in the "Moderate" range and is stable over the past decade.

The cities face different pollutant challenges: Denver, Colorado's dominant issue is fine particulate matter (pm2.5), while Maricopa, Arizona primarily contends with ground-level ozone. This means the seasonal and health risk patterns differ — check each city's individual page for detailed breakdowns.

Frequently Asked Questions

Denver, Colorado has better air quality with a Grade C (52/100) compared to Maricopa, Arizona's Grade F (9/100). Denver, Colorado has a current median AQI of 54 and is stable over the past decade.

Denver, Colorado averages 14 unhealthy air days per year (5-year average), while Maricopa, Arizona averages 126. Unhealthy days are those when AQI exceeds 100 and sensitive groups should limit outdoor activity.

Denver, Colorado's primary pollutant is Fine Particulate Matter (PM2.5), while Maricopa, Arizona's is Ground-Level Ozone. Different dominant pollutants mean different seasonal and health risk patterns.

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