US Cities with Worst Air Quality Overall

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

    Holland, MI

    Population: 107,348Monitored: 302 days
    A
    Median: 40
    Good:235
    Moderate:63
    Sensitive:4
    Unhealthy:
    Very Unhealthy:
    Hazardous:
  2. #27

    Portland, ME

    Population: 210,907Monitored: 304 days
    A
    Median: 39
    Good:225
    Moderate:74
    Sensitive:5
    Unhealthy:
    Very Unhealthy:
    Hazardous:
  3. #28

    Flint, MI

    Population: 295,285Monitored: 303 days
    A
    Median: 38
    Good:252
    Moderate:48
    Sensitive:3
    Unhealthy:
    Very Unhealthy:
    Hazardous:
  4. #29

    Lansing, MI

    Population: 328,527Monitored: 304 days
    A
    Median: 37
    Good:252
    Moderate:49
    Sensitive:3
    Unhealthy:
    Very Unhealthy:
    Hazardous:
  5. #30

    Iowa City, IA

    Population: 133,565Monitored: 304 days
    A
    Median: 36
    Good:216
    Moderate:84
    Sensitive:3
    Unhealthy:1
    Very Unhealthy:
    Hazardous:
  6. #31

    Phoenix, AZ

    Population: 4,121,103Monitored: 304 days
    D
    Median: 71
    Good:50
    Moderate:219
    Sensitive:29
    Unhealthy:4
    Very Unhealthy:1
    Hazardous:1
Previous
12

Protect Your Health from Air Pollution

Living in areas with poor air quality? Learn about air purifiers and other ways to reduce your exposure to harmful pollutants.

Learn About PollutantsCheck Your ZIP Code →