US Cities with Worst PM2.5 Pollution

Cities with the most polluted air based on 2025 EPA monitoring data. These communities face the greatest health risks from air pollution.

Health Impact

40.9M
People in highly polluted areas
8
Avg unhealthy days per city
2122
Highest AQI recorded
Showing 26–31 of 31 cities
  1. #26

    Flint, MI

    Population: 295,285Monitored: 303 days83 days with PM2.5
    A
    Median: 38
    Good:252
    Moderate:48
    Sensitive:3
    Unhealthy:
    Very Unhealthy:
    Hazardous:
  2. #27

    Lansing, MI

    Population: 328,527Monitored: 304 days78 days with PM2.5
    A
    Median: 37
    Good:252
    Moderate:49
    Sensitive:3
    Unhealthy:
    Very Unhealthy:
    Hazardous:
  3. #28

    Logan, UT

    Population: 124,449Monitored: 304 days69 days with PM2.5
    B+
    Median: 46
    Good:186
    Moderate:118
    Sensitive:
    Unhealthy:
    Very Unhealthy:
    Hazardous:
  4. #29

    Phoenix, AZ

    Population: 4,121,103Monitored: 304 days37 days with PM2.5
    D
    Median: 71
    Good:50
    Moderate:219
    Sensitive:29
    Unhealthy:4
    Very Unhealthy:1
    Hazardous:1
  5. #30

    Ogden, UT

    Population: 630,643Monitored: 305 days36 days with PM2.5
    B+
    Median: 47
    Good:187
    Moderate:116
    Sensitive:2
    Unhealthy:
    Very Unhealthy:
    Hazardous:
  6. #31

    St. George, UT

    Population: 148,405Monitored: 304 days19 days with PM2.5
    A-
    Median: 45
    Good:216
    Moderate:88
    Sensitive:
    Unhealthy:
    Very Unhealthy:
    Hazardous:
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