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Which Cities Have the Best and Worst Air Quality in US?


The air quality inside your home or business has a major impact on the people inside. Residents, employees, and other occupants can all have a negative impact on their health and happiness due to low air quality.

The air quality inside any building depends not only on the contaminants inside but on the air outside as well. Research shows that poor air quality plays a factor in upwards of 100,000 deaths in the US each year, highlighting the importance of clean air.

Air quality isn’t the same everywhere throughout the US. We’ve taken a closer look at air quality in different cities based on data from the American Lung Association and the United States Environmental Protection Agency. These are the cities with the best and worst air quality in US today.

Cities With the Best Air Quality in the US


Cheyenne, WY

Cheyenne, Wyoming, has the best air quality US cities have to offer. This city of 65,000 along the Rocky Mountain Front enjoys 24-hour PM10 levels of just 63 µg/m3, showing very low levels of particulate matter along with very low ground-level ozone levels.

Wilmington, NC

The port city of Wilmington, NC, has a population of 116,000 and is among the top air quality ranking by city in the US. 24-hour PM10 levels are 41 µg/m3, and the city demonstrates exceptionally low ozone levels.

Urban Honolulu, HI

It’s no surprise that Urban Honolulu, Hawaii, is a city with best air quality in the US, given the overall air quality of the state. 24-hour PM10 levels are just 34 µg/m3, with other key metrics also highlighting this city’s air quality.

Kahului-Wailuku-Lahaina, HI

Another Hawaiian metropolitan area, Kahului-Wailuku-Lahaina, has a population of 170,00 and is one of the US cities with best air quality that you can find, offering low 24-hour and annual particulate matter levels.

Bangor, ME

Bangor, Maine, takes the list back to the continental states with some of the best air quality on the eastern seaboard. Its 31,000 residents enjoy 24-hour PM10 levels as low as 30 µg/m3.

Casper, WY

Casper is the second entry on this list from Wyoming, with a population of 59,000 enjoying the fresh air and low pollution in this historic oil boomtown. Low ozone and PM levels provide excellent air quality.

Bellingham, WA

The 92,000 residents of Bellingham, Washington, enjoy fresh sea air coming in off of Bellingham Bay, providing exceptionally low pollution levels in this beautiful Pacific Northwest city.

Bismarck, ND

The city of Bismarck, North Dakota, has a population of 133,000 and is one of the best cities in terms of many air quality metrics. Particulate matter, ozone, NO2, SO2, and more are all incredibly low in the area.

Elmira-Corning, NY

This metropolitan statistical area includes a population of 29,00 and has some of the best air quality found throughout New York. It has exceptional 24-hour particulate pollution levels, along with top annual particle pollution levels as well.

Sioux Falls, SD

Sioux Falls, South Dakota, has a population of over 200,000, making it the most populous city on this list of places with best air quality. While it shows higher particulate matter levels than more remote cities on this list, levels are low given its population.

Cities With the Worst Air Quality in the US


Bakersfield, CA

The answer to what city has the worst air quality in the US is Bakersfield, CA. 24-hour PM10 levels as high as 242 µg/m3. The city of 909,000 near the southern end of the San Joaquin Valley also has some of the most high ozone days.

Fresno-Madera-Hanford, CA

Also known as Metropolitan Fresno, this metropolitan area is anchored by Fresno and has a population near 1,200,000. 24-hour PM10 levels reach 230 µg/m3, with annual levels similarly high.

Visalia, CA

Another city in the San Joaquin Valley, Visalia, is one of the places with the worst air quality in the US. 24-hour PM10 levels can reach 198 µg/m3, and ozone and other pollutants are also exceptionally high in this city of 141,000.

San Jose-San Francisco-Oakland, CA

The San Francisco Bay Area is another city with the worst air quality in the US. PM10 levels are better at 76 µg/m3, but other key metrics are very poor. 9.67 million people live in the area.

Los Angeles-Long Beach, CA

The Greater Los Angeles area has a population of 18.5 million people and is one of the places with worst air quality in the country. PM10 levels are around 113 µg/m3, and a variety of other pollutants have high levels.

Medford-Grants Pass, OR

The first city with worst air quality on this list outside of California, Medford-Grants Pass in Oregon, has a population of 285,000. The average PM10 levels are around 108 µg/m3, but this has been strongly influenced by higher numbers of wildfires nearby in the past few years.

Fairbanks, AK

Unlike many other U.S. cities with worst air quality, much of the pollution in Fairbanks, AK, comes from wood-burning stoves. The city of 32,000 has PM10 levels are around 57 µg/m3, which is very high for Alaska.

Phoenix-Mesa-Scottsdale, AZ

The Phoenix Metropolitan area is home to more than 4.8 million residents and is one of the US cities with worst air quality. The heat leads to the area being highly susceptible to ozone pollution, and desert dust plays a huge factor as well.

Chico, CA

This city with worst air quality in US is located in the Sacramento Valley region and has a population of 101,000. PM10 levels are around 129 µg/m3, and the local universities and colleges that drive much of the economy often have to issue warnings for students.

El Centro, CA

In terms of particulate matter alone, El Centro, CA, is a good answer to which city has the worst air quality in the US. The PM10 levels can reach 279 µg/mfor brief periods, making it one place with the worst air quality in the country.

Enjoy Clean Air Even in Places With Bad Air Quality

Of course, the air outside has an impact on your life. However, you can still enjoy clean air inside your home or business with the right quality filters, even in places with bad air quality. Whether you enjoy US cities best air quality or have to deal with the worst, quality filters for your HVAC systems are vital to your health and happiness.

Filter King provides a full range of brands and sizes to fit any HVAC system. You can find the perfect air filter for your needs, with premium options to deal with low outdoor air quality.