The 25 Dirtiest Cities in America, Mapped

Air quality, waste management, and pollution control aren’t just environmental concerns—they’re also a big part of a city’s livability. LawnStarter’s 2025 “Dirtiest Cities in America” ranking looked at 20 factors across 303 major U.S. cities, from industrial emissions and roadway pollution to the share of residents unhappy with their environment. The results show a mix of repeat offenders and surprising newcomers.

1. America’s 25 Dirtiest Cities Are ...
2. The Dirtiest Cities in America, Mapped
3. The 10 Cleanest Cities in America
4. All 303 Cities in the Analysis, Ranked

America’s 25 Dirtiest Cities Are ...

For the second year in a row, San Bernardino, California, ranks as the dirtiest city in the country. Seventy-five percent of residents report dissatisfaction with local pollution. It’s also one of 10 California cities tied for worst median air quality. Adding to the challenge, San Bernardino County has over 850 warehouses of 100,000 square feet or larger, which may contribute to higher nitrogen dioxide levels.

Los Angeles comes in at No. 2, ranking high for near-roadway pollution—nearly 40 percent of residents live near heavily trafficked roads—and overcrowded homes. In third place is Detroit, Michigan, where high smoking rates and public dissatisfaction drive its poor score. Reading, Pennsylvania comes in fourth, with greenhouse gas emissions and a top-ranked toxic release score pushing it up the list. Ontario, California, rounds out the top five, despite making strides in sustainable development and clean energy initiatives. Read on for the top 25 and their scores.

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The Dirtiest Cities in America, Mapped

The 10 Cleanest Cities in America

At the other end of the spectrum, the cleanest city in the ranking is South Bend, Indiana, which boasts good air and water quality, efficient waste management, and high resident satisfaction. Other cities in the top tier include Wilmington, North Carolina; Des Moines, Iowa; Davenport, Iowa; and Athens, Georgia. See the top 10 below with their scores.

1. South Bend, Indiana: 18.53
2. Wilmington, North Carolina: 18.59
3. Des Moines, Iowa: 19.14
4. Davenport, Iowa: 19.45
5. Athens, Georgia: 19.47
6. Winston-Salem, North Carolina: 19.54
7. Fargo, North Dakota: 19.58
8. Frederick, Maryland: 19.91
9. Pleasanton, California: 20.08
10. Lynchburg, Virginia: 20.27

All 303 Cities in the Analysis, Ranked

Curious where your city, or the city nearest you, ended up in the full ranking? Check out the table below.

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