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Unhealthy Air Days
Source EPA Air Quality System, 2024 Provenance US federal agency · primary Agency U.S. Environmental Protection Agency Years 2024 Unit count Geography County (986 published) Counted among Days with an Air Quality Index reading Coverage 31% of counties Highest Riverside County, California, 147 Lowest Ponce Municipio, Puerto Rico, 0 Days when the Air Quality Index passed 100, the point at which the EPA warns sensitive groups to limit exertion outdoors. Counts every category above that line together.
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Highest counties
County Unhealthy Air Days Riverside County, California 147 San Bernardino County, California 144 Los Angeles County, California 133 Tulare County, California 111 Kern County, California 94 Fresno County, California 79 Maricopa County, Arizona 73 Pinal County, Arizona 70 El Paso County, Texas 63 Cameron County, Texas 61 San Diego County, California 52 Imperial County, California 50
Lowest counties
County Unhealthy Air Days Ponce Municipio, Puerto Rico 0 Mayagüez Municipio, Puerto Rico 0 Guaynabo Municipio, Puerto Rico 0 Guayama Municipio, Puerto Rico 0 Fajardo Municipio, Puerto Rico 0 Washakie County, Wyoming 0 Uinta County, Wyoming 0 Park County, Wyoming 0 Lincoln County, Wyoming 0 Carbon County, Wyoming 0 Walworth County, Wisconsin 0 Vilas County, Wisconsin 0
Counted among: Days with an Air Quality Index reading