Home / Trends / Stable Cities With Stable Air Quality These cities have maintained consistent air quality over the past decade with no significant improvement or decline.
All Stable Cities City State 5yr Avg AQI Grade Trend Worst Pollutant Carroll, Virginia VA 8 A -0.2/yr PM10 Fremont, Colorado CO 13 A -0.1/yr PM10 Apache, Arizona AZ 13 A -0.0/yr PM10 Custer, Idaho ID 8 A -0.2/yr PM2.5 Custer, Oklahoma OK 14 A -0.1/yr PM10 Routt, Colorado CO 14 A -0.1/yr PM10 Mohave, Arizona AZ 17 B -0.2/yr PM10 Pitkin, Colorado CO 13 B +0.1/yr PM10 Aleutians East, Alaska AK 12 B -0.1/yr PM2.5 Kenai Peninsula, Alaska AK 10 B +0.0/yr PM2.5 Roosevelt, Montana MT 14 B -0.1/yr PM2.5 San Juan, Colorado CO 9 B +0.1/yr PM2.5 Socorro, New Mexico NM 15 B -0.3/yr PM2.5 Catron, New Mexico NM 13 B -0.0/yr PM2.5 Keweenaw, Michigan MI 13 B -0.1/yr PM2.5 Lake, Montana MT 10 B +0.1/yr PM2.5 Lincoln, New Mexico NM 14 B -0.0/yr PM2.5 Sherman, Kansas KS 16 B +0.1/yr PM10 Wayne, Utah UT 11 B +0.1/yr PM2.5 Los Alamos, New Mexico NM 13 B +0.1/yr PM2.5 Powell, Montana MT 11 B +0.2/yr PM2.5 Thomas, Nebraska NE 17 B -0.1/yr PM2.5 Brooke, West Virginia WV 19 B +0.2/yr PM10 Platte, Wyoming WY 16 B +0.0/yr PM10 Prowers, Colorado CO 17 B +0.2/yr PM10 Sheridan, Montana MT 16 B +0.0/yr PM2.5 Park, Wyoming WY 20 B -0.1/yr PM2.5 Chase, Kansas KS 26 B -0.3/yr PM2.5 Chaves, New Mexico NM 24 B -0.1/yr PM2.5 Franklin, Washington WA 22 B -0.2/yr PM2.5 Klickitat, Washington WA 22 B -0.1/yr PM2.5 Carlton, Minnesota MN 29 B -0.3/yr Ozone Potter, Texas TX 28 B -0.2/yr PM2.5 Whitman, Washington WA 23 B -0.2/yr PM2.5 Ascension, Louisiana LA 32 B -0.3/yr Ozone Benton, Oregon OR 22 B +0.1/yr PM2.5 Macon, North Carolina NC 31 B -0.1/yr Ozone Manatee, Florida FL 34 B -0.2/yr Ozone Saratoga, New York NY 32 B -0.1/yr Ozone St. James, Louisiana LA 30 B -0.1/yr Ozone Victoria, Texas TX 31 B -0.1/yr Ozone Belknap, New Hampshire NH 32 B -0.0/yr Ozone Chattooga, Georgia GA 36 B -0.3/yr Ozone Elk, Pennsylvania PA 35 B -0.2/yr Ozone Elmore, Alabama AL 35 B -0.3/yr Ozone Greenup, Kentucky KY 36 B -0.2/yr Ozone Hall, Nebraska NE 29 B -0.0/yr PM2.5 Ponce, Puerto Rico PR 29 B +0.2/yr PM10 Prince Edward, Virginia VA 33 B -0.1/yr Ozone Somerset, Pennsylvania PA 35 B -0.1/yr Ozone St. John the Baptist, Louisiana LA 33 B -0.1/yr Ozone Tucker, West Virginia WV 35 B -0.1/yr Ozone Williams, North Dakota ND 34 B -0.1/yr Ozone Avery, North Carolina NC 39 B -0.3/yr Ozone Chesterfield, Virginia VA 38 B -0.2/yr Ozone Claiborne, Tennessee TN 35 B -0.1/yr Ozone Clark, Arkansas AR 33 B +0.1/yr Ozone Columbia, Oregon OR 29 B -0.0/yr PM2.5 Delaware, Indiana IN 37 B -0.3/yr Ozone Denali, Alaska AK 34 B +0.1/yr Ozone Edmonson, Kentucky KY 38 B -0.3/yr Ozone Fayette, Ohio OH 36 B -0.2/yr Ozone Flagler, Florida FL 33 B -0.0/yr Ozone Hamilton, New York NY 34 B +0.0/yr Ozone Hanover, Virginia VA 38 B -0.3/yr Ozone Jefferson, New York NY 33 B -0.0/yr Ozone Kent, Rhode Island RI 35 B -0.2/yr Ozone Knox, Maine ME 34 B -0.1/yr Ozone Lawrence, Pennsylvania PA 33 B -0.0/yr Ozone Liberty, Florida FL 32 B +0.1/yr Ozone Morgan, Kentucky KY 35 B -0.0/yr Ozone Morris, New Jersey NJ 36 B -0.2/yr Ozone Polk, Arkansas AR 38 B -0.3/yr Ozone St. Lucie, Florida FL 34 B -0.1/yr Ozone Sumter, Georgia GA 36 B -0.1/yr Ozone Virginia Beach City, Virginia VA 35 B -0.2/yr PM2.5 Wayne, New York NY 34 B -0.1/yr Ozone Adams, Ohio OH 34 B +0.0/yr PM2.5 Big Horn, Wyoming WY 38 B -0.2/yr Ozone Cabell, West Virginia WV 40 B -0.2/yr Ozone Caldwell, North Carolina NC 39 B -0.2/yr Ozone Carter, Kentucky KY 37 B -0.1/yr Ozone Carteret, North Carolina NC 36 B -0.1/yr Ozone Chautauqua, New York NY 37 B -0.2/yr Ozone Clark, Washington WA 34 B -0.3/yr PM2.5 DeKalb, Tennessee TN 35 B +0.0/yr Ozone Delaware, Ohio OH 39 B -0.2/yr Ozone Dutchess, New York NY 34 B +0.1/yr Ozone Fauquier, Virginia VA 35 B -0.0/yr Ozone Giles, Virginia VA 38 B -0.1/yr Ozone Grant, Washington WA 26 B +0.1/yr PM2.5 Granville, North Carolina NC 41 B -0.3/yr Ozone Gregg, Texas TX 34 B +0.1/yr Ozone Hillsborough, New Hampshire NH 38 B -0.2/yr Ozone Huron, Michigan MI 37 B -0.2/yr Ozone Lake, Florida FL 35 B +0.1/yr Ozone Lauderdale, Mississippi MS 34 B +0.0/yr Ozone Licking, Ohio OH 40 B -0.2/yr Ozone Loudoun, Virginia VA 37 B -0.1/yr Ozone Luzerne, Pennsylvania PA 34 B +0.1/yr Ozone Madison, Tennessee TN 38 B -0.3/yr PM2.5 Monongalia, West Virginia WV 40 B -0.2/yr Ozone Noble, Ohio OH 37 B -0.1/yr Ozone Oswego, New York NY 33 B +0.1/yr Ozone Pike, Georgia GA 36 B -0.1/yr Ozone Polk, Texas TX 32 B +0.3/yr Ozone Putnam, New York NY 34 B +0.1/yr Ozone Rockingham, Virginia VA 36 B -0.1/yr Ozone Suffolk City, Virginia VA 38 B -0.1/yr Ozone Tompkins, New York NY 35 B +0.0/yr Ozone Tuscola, Michigan MI 33 B -0.0/yr Ozone Wexford, Michigan MI 34 B -0.0/yr Ozone Windham, Connecticut CT 35 B 0.0/yr Ozone Wood, Ohio OH 38 B -0.2/yr Ozone Wythe, Virginia VA 39 B -0.1/yr Ozone Yellowstone, Montana MT 33 B -0.2/yr PM2.5 Anderson, Tennessee TN 39 B -0.1/yr Ozone Ashtabula, Ohio OH 39 B -0.2/yr Ozone Baker, Oregon OR 31 B +0.1/yr PM2.5 Bennington, Vermont VT 37 B -0.1/yr Ozone Berkeley, South Carolina SC 34 B +0.2/yr Ozone Caddo, Louisiana LA 38 B -0.0/yr Ozone Charles, Virginia VA 35 B +0.1/yr Ozone Clackamas, Oregon OR 32 B -0.1/yr PM2.5 Clinton, Ohio OH 41 B -0.2/yr Ozone Coos, New Hampshire NH 42 B -0.3/yr Ozone Douglas, Georgia GA 38 B -0.2/yr Ozone Fond du Lac, Wisconsin WI 38 B -0.1/yr Ozone Geauga, Ohio OH 41 B -0.3/yr Ozone Hampshire, Massachusetts MA 39 B -0.2/yr Ozone Hancock, Maine ME 37 B -0.1/yr Ozone Hancock, West Virginia WV 37 B -0.0/yr Ozone Highlands, Florida FL 34 B +0.3/yr Ozone Hunt, Texas TX 35 B +0.1/yr Ozone Jackson, Arkansas AR 41 B -0.2/yr PM2.5 Jo Daviess, Illinois IL 34 B +0.1/yr Ozone Knox, Ohio OH 40 B -0.1/yr Ozone Lake, Oregon OR 27 B -0.1/yr PM2.5 Lancaster, Nebraska NE 37 B 0.0/yr Ozone Lincoln, North Carolina NC 41 B -0.2/yr Ozone Madison, Ohio OH 41 B -0.2/yr Ozone Marathon, Wisconsin WI 35 B +0.0/yr Ozone Mason, Michigan MI 37 B -0.1/yr Ozone Miami, Ohio OH 40 B -0.1/yr Ozone Monmouth, New Jersey NJ 37 B -0.0/yr Ozone Monroe, Missouri MO 34 B +0.2/yr Ozone Murray, Georgia GA 39 B -0.1/yr Ozone Norfolk, Massachusetts MA 37 B -0.1/yr Ozone Osceola, Florida FL 34 B +0.2/yr Ozone Oxford, Maine ME 35 B +0.0/yr PM2.5 Pasco, Florida FL 36 B +0.1/yr Ozone Passaic, New Jersey NJ 39 B -0.2/yr Ozone Pointe Coupee, Louisiana LA 33 B +0.2/yr Ozone Rockingham, North Carolina NC 41 B -0.3/yr Ozone Trigg, Kentucky KY 36 B +0.1/yr Ozone Union, South Dakota SD 40 B -0.2/yr Ozone Wabash, Indiana IN 36 B +0.1/yr Ozone Wallowa, Oregon OR 27 B +0.3/yr PM2.5 Washington, Kentucky KY 37 B +0.1/yr Ozone Washington, Maine ME 34 B +0.2/yr Ozone Washington, Ohio OH 40 B -0.1/yr Ozone Washington, Rhode Island RI 37 B -0.1/yr Ozone Wilson, Tennessee TN 38 B -0.0/yr Ozone Yalobusha, Mississippi MS 33 B +0.3/yr Ozone Baldwin, Alabama AL 39 B +0.1/yr Ozone Barnstable, Massachusetts MA 36 B +0.2/yr Ozone Boone, Missouri MO 38 B +0.1/yr Ozone Gallatin, Montana MT 32 B -0.0/yr PM2.5 Hancock, Kentucky KY 40 B -0.1/yr Ozone Jessamine, Kentucky KY 40 B -0.0/yr Ozone Leavenworth, Kansas KS 35 B +0.2/yr Ozone Lee, Iowa IA 42 B -0.3/yr PM2.5 Lorain, Ohio OH 39 B -0.1/yr PM2.5 Manistee, Michigan MI 36 B +0.1/yr Ozone Mayes, Oklahoma OK 37 B +0.2/yr Ozone Muskegon, Michigan MI 39 B -0.3/yr Ozone Newton, Arkansas AR 37 B +0.2/yr Ozone Okaloosa, Florida FL 36 B +0.3/yr Ozone Palm Beach, Florida FL 42 B -0.3/yr PM2.5 Person, North Carolina NC 40 B -0.1/yr Ozone Rio Arriba, New Mexico NM 43 B -0.2/yr Ozone Rutland, Vermont VT 39 B -0.1/yr PM2.5 Sainte Genevieve, Missouri MO 40 B -0.1/yr Ozone Santa Cruz, California CA 37 B -0.2/yr PM2.5 Vilas, Wisconsin WI 34 B +0.2/yr Ozone Washington, Oregon OR 36 B -0.1/yr PM2.5 Weston, Wyoming WY 41 B -0.0/yr Ozone Alachua, Florida FL 40 B +0.0/yr PM2.5 Anderson, South Carolina SC 39 B +0.2/yr Ozone Bristol, Massachusetts MA 41 B -0.0/yr Ozone Callaway, Missouri MO 39 B +0.1/yr Ozone Carbon, Utah UT 44 B -0.3/yr Ozone Carroll, Maryland MD 42 B -0.0/yr Ozone Clinton, Missouri MO 40 B -0.0/yr Ozone Cochise, Arizona AZ 45 B -0.2/yr Ozone Converse, Wyoming WY 41 B -0.1/yr Ozone Cumberland, North Carolina NC 44 B -0.3/yr PM2.5 Effingham, Illinois IL 39 B +0.1/yr Ozone Essex, Massachusetts MA 41 B +0.0/yr Ozone Frederick, Maryland MD 42 B -0.1/yr Ozone Garland, Arkansas AR 45 B -0.3/yr PM2.5 Gloucester, New Jersey NJ 40 B -0.1/yr Ozone Glynn, Georgia GA 39 B +0.1/yr PM2.5 Haywood, North Carolina NC 43 B -0.2/yr Ozone Jackson, South Dakota SD 39 B +0.1/yr Ozone Kent, Delaware DE 43 B -0.1/yr Ozone Livingston, Kentucky KY 40 B +0.1/yr Ozone Manitowoc, Wisconsin WI 38 B +0.1/yr Ozone Middlesex, Connecticut CT 40 B -0.3/yr Ozone Multnomah, Oregon OR 36 B +0.0/yr PM2.5 Navarro, Texas TX 43 B -0.1/yr PM2.5 Oldham, Kentucky KY 40 B +0.0/yr Ozone Perry, Missouri MO 40 B +0.0/yr Ozone Richland, Montana MT 38 B +0.1/yr Ozone Roanoke, Virginia VA 42 B -0.1/yr PM2.5 Saint Louis, Minnesota MN 39 B -0.2/yr PM2.5 Sarasota, Florida FL 45 B -0.2/yr PM2.5 Schoolcraft, Michigan MI 35 B +0.3/yr PM2.5 Sevier, Tennessee TN 43 B -0.0/yr Ozone Simpson, Kentucky KY 39 B +0.1/yr Ozone Tangipahoa, Louisiana LA 39 B +0.1/yr PM2.5 Tolland, Connecticut CT 40 B -0.0/yr Ozone Valencia, New Mexico NM 43 B -0.1/yr Ozone Yavapai, Arizona AZ 43 B 0.0/yr Ozone Adair, Oklahoma OK 42 C -0.0/yr PM2.5 Albany, New York NY 41 C -0.0/yr PM2.5 Billings, North Dakota ND 37 C +0.3/yr Ozone Brewster, Texas TX 42 C +0.1/yr Ozone Cedar, Missouri MO 42 C +0.0/yr PM2.5 Chelan, Washington WA 32 C -0.0/yr PM2.5 Collier, Florida FL 41 C +0.1/yr PM2.5 DeKalb, Alabama AL 40 C +0.3/yr Ozone Door, Wisconsin WI 37 C +0.1/yr Ozone Edgefield, South Carolina SC 41 C +0.1/yr PM2.5 Franklin, Massachusetts MA 42 C -0.0/yr PM2.5 Frederick, Virginia VA 42 C -0.1/yr PM2.5 Guilford, North Carolina NC 45 C -0.2/yr PM2.5 Henrico, Virginia VA 43 C -0.0/yr PM2.5 Jefferson, Wisconsin WI 39 C -0.0/yr Ozone Kewaunee, Wisconsin WI 38 C +0.1/yr Ozone McKenzie, North Dakota ND 36 C +0.2/yr Ozone Monroe, Indiana IN 41 C -0.0/yr PM2.5 Monterey, California CA 40 C +0.1/yr Ozone Montezuma, Colorado CO 44 C -0.0/yr Ozone Montgomery, North Carolina NC 44 C -0.1/yr PM2.5 Ocean, New Jersey NJ 40 C -0.1/yr PM2.5 Parker, Texas TX 37 C +0.2/yr Ozone Phillips, Montana MT 36 C +0.3/yr Ozone Plymouth, Massachusetts MA 41 C +0.1/yr PM2.5 San Benito, California CA 41 C +0.0/yr Ozone Sullivan, Tennessee TN 41 C +0.0/yr PM2.5 Trumbull, Ohio OH 44 C -0.2/yr PM2.5 Wakulla, Florida FL 40 C +0.1/yr PM2.5 Warren, Kentucky KY 44 C -0.2/yr PM2.5 Yancey, North Carolina NC 44 C -0.0/yr Ozone Andrew, Missouri MO 41 C +0.2/yr Ozone Bibb, Georgia GA 47 C -0.2/yr PM2.5 Brazoria, Texas TX 34 C +0.2/yr Ozone Bullitt, Kentucky KY 40 C +0.3/yr Ozone Chittenden, Vermont VT 40 C +0.3/yr Ozone Columbia, Wisconsin WI 39 C +0.2/yr Ozone Daviess, Kentucky KY 47 C -0.2/yr PM2.5 Essex, New York NY 41 C +0.2/yr Ozone Flathead, Montana MT 40 C -0.1/yr PM2.5 Graham, North Carolina NC 43 C +0.1/yr Ozone Hampton City, Virginia VA 41 C +0.2/yr PM2.5 Hood, Texas TX 36 C +0.3/yr Ozone Hunterdon, New Jersey NJ 43 C +0.2/yr Ozone Johnston, North Carolina NC 43 C +0.0/yr PM2.5 Laramie, Wyoming WY 43 C -0.1/yr Ozone Lenawee, Michigan MI 45 C -0.1/yr PM2.5 Mahoning, Ohio OH 46 C -0.2/yr PM2.5 Monroe, New York NY 42 C +0.1/yr PM2.5 Natrona, Wyoming WY 42 C +0.1/yr Ozone Navajo, Arizona AZ 44 C +0.2/yr Ozone New London, Connecticut CT 40 C -0.1/yr PM2.5 Pennington, South Dakota SD 38 C +0.0/yr PM2.5 Pierce, Washington WA 43 C -0.1/yr Ozone Pottawattamie, Iowa IA 42 C +0.1/yr PM2.5 Preble, Ohio OH 45 C -0.1/yr PM2.5 Rowan, North Carolina NC 45 C -0.1/yr PM2.5 Saint Charles, Missouri MO 42 C -0.1/yr Ozone San Juan, Utah UT 44 C +0.1/yr Ozone Santa Fe, New Mexico NM 44 C +0.2/yr Ozone St. Bernard, Louisiana LA 48 C -0.2/yr PM2.5 Washington, Utah UT 44 C +0.0/yr Ozone White Pine, Nevada NV 44 C +0.2/yr Ozone Albemarle, Virginia VA 42 C +0.3/yr PM2.5 Anoka, Minnesota MN 41 C +0.2/yr Ozone Bergen, New Jersey NJ 46 C -0.3/yr PM2.5 Brown, Wisconsin WI 41 C +0.1/yr PM2.5 Coconino, Arizona AZ 45 C +0.1/yr Ozone Custer, South Dakota SD 41 C +0.2/yr Ozone Fayette, Kentucky KY 45 C +0.1/yr PM2.5 Hamilton, Florida FL 46 C +0.0/yr PM2.5 Houston, Georgia GA 48 C -0.2/yr PM2.5 Jefferson, Louisiana LA 44 C +0.1/yr PM2.5 Johnson, Texas TX 38 C +0.2/yr Ozone Kaufman, Texas TX 43 C +0.1/yr PM2.5 Lea, New Mexico NM 44 C +0.1/yr Ozone Lincoln, Missouri MO 40 C +0.3/yr Ozone Madison, Indiana IN 46 C -0.2/yr PM2.5 Marion, Florida FL 44 C +0.2/yr PM2.5 Marshall, West Virginia WV 49 C -0.2/yr PM2.5 Martin, Florida FL 42 C +0.2/yr PM2.5 Montgomery, Pennsylvania PA 44 C +0.0/yr PM2.5 Muscogee, Georgia GA 46 C 0.0/yr PM2.5 Randall, Texas TX 43 C +0.3/yr Ozone Rock, Wisconsin WI 40 C +0.3/yr Ozone Santa Rosa, Florida FL 45 C +0.1/yr PM2.5 St. Clair, Michigan MI 44 C -0.2/yr PM2.5 Summit, Ohio OH 46 C -0.2/yr PM2.5 Sumner, Tennessee TN 43 C +0.1/yr PM2.5 Umatilla, Oregon OR 39 C +0.2/yr PM2.5 Vanderburgh, Indiana IN 49 C -0.3/yr PM2.5 Walworth, Wisconsin WI 40 C +0.3/yr Ozone Warren, New Jersey NJ 41 C +0.3/yr PM2.5 Whitley, Indiana IN 47 C -0.1/yr PM2.5 Worcester, Massachusetts MA 43 C +0.2/yr Ozone Adams, Pennsylvania PA 46 C +0.1/yr Ozone Blount, Tennessee TN 45 C +0.3/yr Ozone Charleston, South Carolina SC 45 C +0.2/yr PM2.5 Chatham, Georgia GA 47 C +0.1/yr PM2.5 Clark, Ohio OH 49 C -0.1/yr PM2.5 Comanche, Oklahoma OK 46 C +0.2/yr Ozone Dewey, Oklahoma OK 45 C +0.3/yr PM2.5 Greene, Missouri MO 44 C +0.2/yr PM2.5 Gunnison, Colorado CO 46 C +0.2/yr Ozone Hampden, Massachusetts MA 44 C +0.2/yr PM2.5 Kent, Michigan MI 45 C -0.1/yr PM2.5 Knox, Tennessee TN 49 C -0.1/yr PM2.5 La Paz, Arizona AZ 45 C +0.3/yr Ozone La Plata, Colorado CO 46 C +0.2/yr Ozone Livingston, Louisiana LA 50 C -0.1/yr PM2.5 Mercer, New Jersey NJ 46 C -0.2/yr PM2.5 Montgomery, Alabama AL 50 C -0.1/yr PM2.5 Morgan, Alabama AL 45 C +0.2/yr PM2.5 Orange, Texas TX 44 C +0.2/yr PM2.5 Pinellas, Florida FL 47 C +0.2/yr PM2.5 Racine, Wisconsin WI 41 C +0.2/yr Ozone Sheboygan, Wisconsin WI 41 C +0.2/yr Ozone Teton, Wyoming WY 43 C +0.1/yr Ozone Washtenaw, Michigan MI 46 C -0.1/yr PM2.5 West Baton Rouge, Louisiana LA 47 C -0.1/yr PM2.5 Beaver, Pennsylvania PA 51 C -0.2/yr PM2.5 Boise, Idaho ID 43 C +0.1/yr PM2.5 Campbell, Wyoming WY 44 C +0.1/yr Ozone Davidson, Tennessee TN 52 C -0.2/yr PM2.5 Dougherty, Georgia GA 51 C -0.1/yr PM2.5 Fairfax, Virginia VA 47 C +0.1/yr PM2.5 Forsyth, North Carolina NC 49 C -0.0/yr PM2.5 Fremont, Wyoming WY 46 C +0.3/yr Ozone Gwinnett, Georgia GA 48 C +0.0/yr PM2.5 Hidalgo, Texas TX 48 C +0.1/yr PM2.5 Hillsborough, Florida FL 51 C -0.1/yr PM2.5 Hinds, Mississippi MS 53 C -0.2/yr PM2.5 Lee, North Carolina NC 52 C 0.0/yr PM2.5 Lewis and Clark, Montana MT 44 C +0.2/yr Ozone Mobile, Alabama AL 49 C +0.2/yr PM2.5 Randolph, Illinois IL 45 C +0.2/yr PM2.5 Rio Blanco, Colorado CO 47 C +0.3/yr Ozone Snohomish, Washington WA 38 C +0.3/yr PM2.5 Sublette, Wyoming WY 46 C +0.0/yr Ozone Sweetwater, Wyoming WY 46 C +0.0/yr Ozone Walker, Georgia GA 50 C +0.0/yr PM2.5 Baltimore, Maryland MD 45 C +0.2/yr Ozone Carson City, Nevada NV 44 C -0.0/yr Ozone Contra Costa, California CA 48 C -0.1/yr PM2.5 DeSoto, Mississippi MS 48 C +0.2/yr PM2.5 El Dorado, California CA 43 C -0.2/yr Ozone Forrest, Mississippi MS 50 C +0.2/yr PM2.5 Franklin, Ohio OH 50 C +0.0/yr PM2.5 Greenville, South Carolina SC 49 C +0.2/yr PM2.5 Harrison, Mississippi MS 48 C +0.3/yr PM2.5 Kenosha, Wisconsin WI 45 C -0.1/yr Ozone Nueces, Texas TX 47 C +0.2/yr PM2.5 Outagamie, Wisconsin WI 43 C +0.3/yr PM2.5 Peoria, Illinois IL 47 C +0.1/yr PM2.5 Polk, Iowa IA 44 C +0.3/yr PM2.5 San Juan, New Mexico NM 46 C +0.2/yr Ozone Santa Clara, California CA 49 C -0.2/yr PM2.5 St. Joseph, Indiana IN 50 C -0.1/yr PM2.5 Utah, Utah UT 48 C +0.0/yr Ozone Yuma, Arizona AZ 48 C +0.1/yr Ozone Albany, Wyoming WY 48 C +0.3/yr Ozone Benewah, Idaho ID 48 C -0.1/yr PM2.5 Bowie, Texas TX 51 C +0.2/yr PM2.5 Calcasieu, Louisiana LA 52 C +0.2/yr PM2.5 Clark, Indiana IN 50 C +0.2/yr PM2.5 El Paso, Colorado CO 46 C +0.2/yr Ozone Fulton, Georgia GA 53 C -0.2/yr PM2.5 Jefferson, Texas TX 48 C +0.1/yr PM2.5 Lake, Indiana IN 53 C -0.3/yr PM2.5 Pulaski, Arkansas AR 53 C +0.1/yr PM2.5 Queens, New York NY 46 C +0.2/yr PM2.5 Shelby, Tennessee TN 50 C -0.0/yr PM2.5 Clear Creek, Colorado CO 48 C +0.1/yr Ozone Colusa, California CA 47 C +0.0/yr PM2.5 Jefferson, Kentucky KY 54 C -0.3/yr PM2.5 Montgomery, Ohio OH 51 C +0.3/yr PM2.5 Montgomery, Texas TX 48 C +0.3/yr PM2.5 Shasta, California CA 44 C +0.2/yr Ozone Tehama, California CA 45 C -0.1/yr Ozone Washoe, Nevada NV 50 C -0.3/yr Ozone Wyandotte, Kansas KS 50 C +0.0/yr PM2.5 Cache, Utah UT 47 C +0.3/yr Ozone Jackson, Oregon OR 44 C -0.1/yr PM2.5 Tulsa, Oklahoma OK 51 C -0.0/yr PM2.5 Will, Illinois IL 51 C +0.2/yr PM2.5 Dallas, Texas TX 50 C -0.1/yr PM2.5 Gila, Arizona AZ 46 C +0.2/yr Ozone Lancaster, Pennsylvania PA 55 C -0.1/yr PM2.5 Allegheny, Pennsylvania PA 56 C -0.2/yr PM2.5 Arapahoe, Colorado CO 46 C +0.2/yr Ozone Denton, Texas TX 46 C +0.1/yr Ozone Jefferson, Alabama AL 57 C +0.1/yr PM2.5 Nevada, California CA 47 C -0.1/yr Ozone St. Louis City, Missouri MO 55 C +0.2/yr PM2.5 Denver, Colorado CO 54 C 0.0/yr PM2.5 Lane, Oregon OR 45 C +0.1/yr PM2.5 Bexar, Texas TX 54 C +0.3/yr PM2.5 Larimer, Colorado CO 51 C +0.1/yr Ozone Marion, Indiana IN 57 C +0.2/yr PM2.5 Klamath, Oregon OR 44 C +0.2/yr PM2.5 Wayne, Michigan MI 58 C +0.2/yr PM2.5 Cook, Illinois IL 57 D -0.1/yr PM2.5 Dona Ana, New Mexico NM 54 D -0.1/yr Ozone Jefferson, Colorado CO 47 D +0.3/yr Ozone Clark, Nevada NV 62 D +0.2/yr Ozone San Diego, California CA 67 D +0.1/yr PM2.5
Frequently Asked Questions How many US cities have stable air quality? 430 of 1,020 monitored US cities currently show stable air quality trends based on 10-year EPA data.
What causes air quality to remain stable? Stable air quality often means that emission reduction gains are being offset by other factors like population growth, traffic increases, or periodic wildfire smoke events.
How is the air quality trend calculated? Trend is calculated using a linear regression of annual median AQI values over the most recent 10 years of data. Cities with a slope below -0.1 AQI/year are classified as Improving, above +0.1 as Worsening, and between as Stable.