US City Air Quality Rankings

Compare air quality across major US cities based on 2025 EPA data. Rankings are calculated using median AQI values from cities with at least 300 days of monitoring data.

39
National Avg AQI
153237
Total Good Days
50492
Total Moderate Days
56
Total Unhealthy Days

Cleanest Air Cities

🏆
  1. #1

    Pocatello, ID

    Median AQI: 31 • 278 good days
    →
  2. #2

    Iowa City, IA

    Median AQI: 36 • 216 good days
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  3. #3

    Lansing, MI

    Median AQI: 37 • 252 good days
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  4. #4

    Flint, MI

    Median AQI: 38 • 252 good days
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  5. #5

    Portland, ME

    Median AQI: 39 • 225 good days
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  6. #6

    Port Huron, MI

    Median AQI: 39 • 225 good days
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  7. #7

    Holland, MI

    Median AQI: 40 • 235 good days
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  8. #8

    Kalamazoo, MI

    Median AQI: 40 • 225 good days
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  9. #9

    Rockville, MD

    Median AQI: 41 • 253 good days
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  10. #10

    Aspen Hill, MD

    Median AQI: 41 • 253 good days
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View All Best Cities →

Most Polluted Cities

⚠️
  1. #1

    Peoria, AZ

    Median AQI: 71 • 6 unhealthy days
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  2. #2

    Glendale, AZ

    Median AQI: 71 • 6 unhealthy days
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  3. #3

    Surprise, AZ

    Median AQI: 71 • 6 unhealthy days
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  4. #4

    Tempe, AZ

    Median AQI: 71 • 6 unhealthy days
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  5. #5

    Scottsdale, AZ

    Median AQI: 71 • 6 unhealthy days
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  6. #6

    Queen Creek, AZ

    Median AQI: 71 • 6 unhealthy days
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  7. #7

    Buckeye, AZ

    Median AQI: 71 • 6 unhealthy days
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  8. #8

    Goodyear, AZ

    Median AQI: 71 • 6 unhealthy days
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  9. #9

    Avondale, AZ

    Median AQI: 71 • 6 unhealthy days
    →
  10. #10

    Chandler, AZ

    Median AQI: 71 • 6 unhealthy days
    →
View All Worst Cities →

Best Small Cities

Cleanest air in cities with 10,000-50,000 people

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Most Improved Cities

Cities with the biggest air quality improvements

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Worst PM2.5 Cities

Cities with highest fine particulate pollution

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How We Calculate Rankings

Rankings are based on 2025 data from the EPA's Air Quality System (AQS). We use median AQI values to rank cities, as this provides a stable measure of typical air quality throughout the year.

Only cities with at least 300 days of monitoring data are included to ensure statistical reliability. Population thresholds are applied to create meaningful comparisons between similar urban areas.

Learn more about our methodology →