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Grade C Air Quality Cities 433 cities with average air quality
Grade C means average air quality with regular moderate-to-unhealthy days for sensitive groups. These cities are scored using EPA Air Quality System data spanning 10 years of daily AQI readings.
All Grade C Cities City State 5yr Avg AQI Trend Worst Pollutant Adair, Oklahoma OK 42 Stable PM2.5 Albany, New York NY 41 Stable PM2.5 Billings, North Dakota ND 37 Stable Ozone Brewster, Texas TX 42 Stable Ozone Bronx, New York NY 46 Improving PM2.5 Cedar, Missouri MO 42 Stable PM2.5 Chelan, Washington WA 32 Stable PM2.5 Collier, Florida FL 41 Stable PM2.5 DeKalb, Alabama AL 40 Stable Ozone DeKalb, Georgia GA 50 Improving PM2.5 Delaware, Pennsylvania PA 51 Improving PM2.5 Door, Wisconsin WI 37 Stable Ozone Edgefield, South Carolina SC 41 Stable PM2.5 Franklin, Massachusetts MA 42 Stable PM2.5 Frederick, Virginia VA 42 Stable PM2.5 Glenn, California CA 43 Improving Ozone Guilford, North Carolina NC 45 Stable PM2.5 Hall, Georgia GA 47 Improving PM2.5 Hamilton, Indiana IN 45 Improving PM2.5 Hennepin, Minnesota MN 47 Improving PM2.5 Henrico, Virginia VA 43 Stable PM2.5 Jefferson, Wisconsin WI 39 Stable Ozone Kewaunee, Wisconsin WI 38 Stable Ozone Knox, Indiana IN 36 Worsening Ozone Lake, Minnesota MN 33 Worsening PM2.5 Lee, Mississippi MS 38 Worsening Ozone McCracken, Kentucky KY 46 Improving PM2.5 McKenzie, North Dakota ND 36 Stable Ozone Monroe, Indiana IN 41 Stable PM2.5 Monterey, California CA 40 Stable Ozone Montezuma, Colorado CO 44 Stable Ozone Montgomery, North Carolina NC 44 Stable PM2.5 New Castle, Delaware DE 48 Improving PM2.5 Ocean, New Jersey NJ 40 Stable PM2.5 Parker, Texas TX 37 Stable Ozone Phillips, Montana MT 36 Stable Ozone Plymouth, Massachusetts MA 41 Stable PM2.5 San Benito, California CA 41 Stable Ozone Scioto, Ohio OH 21 Worsening PM10 Smith, Texas TX 36 Worsening Ozone Spartanburg, South Carolina SC 47 Improving PM2.5 Sullivan, Tennessee TN 41 Stable PM2.5 Trumbull, Ohio OH 44 Stable PM2.5 Wakulla, Florida FL 40 Stable PM2.5 Warren, Kentucky KY 44 Stable PM2.5 Weber, Utah UT 46 Improving Ozone Yancey, North Carolina NC 44 Stable Ozone Andrew, Missouri MO 41 Stable Ozone Bibb, Georgia GA 47 Stable PM2.5 Brazoria, Texas TX 34 Stable Ozone Bullitt, Kentucky KY 40 Stable Ozone Camden, New Jersey NJ 49 Improving PM2.5 Chittenden, Vermont VT 40 Stable Ozone Clinton, Iowa IA 51 Improving PM2.5 Columbia, Wisconsin WI 39 Stable Ozone Daviess, Kentucky KY 47 Stable PM2.5 District of Columbia, District Of Columbia DC 49 Improving PM2.5 Dukes, Massachusetts MA 37 Worsening Ozone Essex, New York NY 41 Stable Ozone Flathead, Montana MT 40 Stable PM2.5 Goodhue, Minnesota MN 38 Worsening Ozone Graham, North Carolina NC 43 Stable Ozone Hampton City, Virginia VA 41 Stable PM2.5 Hood, Texas TX 36 Stable Ozone Hunterdon, New Jersey NJ 43 Stable Ozone Johnston, North Carolina NC 43 Stable PM2.5 King, Washington WA 45 Improving PM2.5 Laramie, Wyoming WY 43 Stable Ozone Lenawee, Michigan MI 45 Stable PM2.5 Mahoning, Ohio OH 46 Stable PM2.5 Monroe, New York NY 42 Stable PM2.5 Natrona, Wyoming WY 42 Stable Ozone Navajo, Arizona AZ 44 Stable Ozone New Hanover, North Carolina NC 39 Worsening PM2.5 New London, Connecticut CT 40 Stable PM2.5 Onondaga, New York NY 38 Worsening Ozone Pennington, South Dakota SD 38 Stable PM2.5 Pierce, Washington WA 43 Stable Ozone Pottawattamie, Iowa IA 42 Stable PM2.5 Preble, Ohio OH 45 Stable PM2.5 Prince William, Virginia VA 35 Worsening Ozone Rowan, North Carolina NC 45 Stable PM2.5 Saint Charles, Missouri MO 42 Stable Ozone San Joaquin, California CA 50 Improving PM2.5 San Juan, Utah UT 44 Stable Ozone San Luis Obispo, California CA 51 Improving PM2.5 Santa Fe, New Mexico NM 44 Stable Ozone St. Bernard, Louisiana LA 48 Stable PM2.5 Steuben, New York NY 38 Worsening Ozone Suffolk, New York NY 42 Improving Ozone Terrebonne, Louisiana LA 38 Worsening PM2.5 Union, New Jersey NJ 51 Improving PM2.5 Vigo, Indiana IN 49 Improving PM2.5 Washington, Utah UT 44 Stable Ozone White Pine, Nevada NV 44 Stable Ozone Woodbury, Iowa IA 40 Worsening PM2.5 Adams, Illinois IL 40 Worsening Ozone Albemarle, Virginia VA 42 Stable PM2.5 Anoka, Minnesota MN 41 Stable Ozone Bergen, New Jersey NJ 46 Stable PM2.5 Boone, Kentucky KY 40 Worsening Ozone Bremer, Iowa IA 38 Worsening Ozone Brevard, Florida FL 43 Worsening PM2.5 Brown, Wisconsin WI 41 Stable PM2.5 Butte, Idaho ID 42 Worsening Ozone Coconino, Arizona AZ 45 Stable Ozone Creek, Oklahoma OK 39 Worsening Ozone Crow Wing, Minnesota MN 36 Worsening PM2.5 Custer, South Dakota SD 41 Stable Ozone Dauphin, Pennsylvania PA 48 Improving PM2.5 Dunn, North Dakota ND 37 Worsening Ozone Elko, Nevada NV 31 Worsening PM10 Fayette, Kentucky KY 45 Stable PM2.5 Forest, Wisconsin WI 38 Worsening Ozone Guaynabo, Puerto Rico PR 29 Worsening NO2 Hamilton, Florida FL 46 Stable PM2.5 Harrison, Iowa IA 40 Worsening Ozone Houston, Georgia GA 48 Stable PM2.5 Jasper, Missouri MO 39 Worsening Ozone Jefferson, Louisiana LA 44 Stable PM2.5 Johnson, Texas TX 38 Stable Ozone Kaufman, Texas TX 43 Stable PM2.5 Kings, New York NY 39 Worsening PM2.5 Knox, Nebraska NE 37 Worsening Ozone Lea, New Mexico NM 44 Stable Ozone Lincoln, Missouri MO 40 Stable Ozone Linn, Oregon OR 35 Worsening PM2.5 Madison, Indiana IN 46 Stable PM2.5 Marion, Florida FL 44 Stable PM2.5 Marion, Oregon OR 37 Worsening PM2.5 Marshall, West Virginia WV 49 Stable PM2.5 Martin, Florida FL 42 Stable PM2.5 Mercer, North Dakota ND 38 Worsening Ozone Merrimack, New Hampshire NH 37 Worsening Ozone Mille Lacs, Minnesota MN 35 Worsening Ozone Montgomery, Pennsylvania PA 44 Stable PM2.5 Muscogee, Georgia GA 46 Stable PM2.5 Pulaski, Kentucky KY 42 Worsening Ozone Randall, Texas TX 43 Stable Ozone Rock, Wisconsin WI 40 Stable Ozone Rockdale, Georgia GA 39 Worsening Ozone Santa Rosa, Florida FL 45 Stable PM2.5 Sheridan, Wyoming WY 41 Worsening Ozone St. Clair, Michigan MI 44 Stable PM2.5 Summit, Ohio OH 46 Stable PM2.5 Sumner, Tennessee TN 43 Stable PM2.5 Taylor, Wisconsin WI 39 Worsening Ozone Umatilla, Oregon OR 39 Stable PM2.5 Vanderburgh, Indiana IN 49 Stable PM2.5 Ventura, California CA 50 Improving PM2.5 Walworth, Wisconsin WI 40 Stable Ozone Warren, New Jersey NJ 41 Stable PM2.5 Whitley, Indiana IN 47 Stable PM2.5 Williamson, Tennessee TN 40 Worsening Ozone Worcester, Massachusetts MA 43 Stable Ozone Adams, Pennsylvania PA 46 Stable Ozone Allen, Ohio OH 42 Worsening Ozone Ashland, Wisconsin WI 36 Worsening Ozone Blaine, Idaho ID 21 Worsening PM2.5 Blount, Tennessee TN 45 Stable Ozone Brookings, South Dakota SD 40 Worsening Ozone Charleston, South Carolina SC 45 Stable PM2.5 Chatham, Georgia GA 47 Stable PM2.5 Clark, Ohio OH 49 Stable PM2.5 Comanche, Oklahoma OK 46 Stable Ozone Dewey, Oklahoma OK 45 Stable PM2.5 Fayette, Pennsylvania PA 43 Worsening PM2.5 Franklin, New York NY 31 Worsening Ozone Greene, Missouri MO 44 Stable PM2.5 Greene, Pennsylvania PA 41 Worsening Ozone Gunnison, Colorado CO 46 Stable Ozone Hampden, Massachusetts MA 44 Stable PM2.5 Indiana, Pennsylvania PA 40 Worsening Ozone Johnston, Oklahoma OK 41 Worsening Ozone Kanawha, West Virginia WV 42 Worsening PM2.5 Kent, Michigan MI 45 Stable PM2.5 Knox, Tennessee TN 49 Stable PM2.5 La Paz, Arizona AZ 45 Stable Ozone La Plata, Colorado CO 46 Stable Ozone Livingston, Louisiana LA 50 Stable PM2.5 Mayagnez, Puerto Rico PR 31 Worsening PM2.5 Meade, South Dakota SD 39 Worsening Ozone Mecklenburg, North Carolina NC 50 Improving PM2.5 Mercer, New Jersey NJ 46 Stable PM2.5 Moffat, Colorado CO 42 Worsening Ozone Montgomery, Alabama AL 50 Stable PM2.5 Morgan, Alabama AL 45 Stable PM2.5 New Haven, Connecticut CT 45 Improving PM2.5 Orange, Texas TX 44 Stable PM2.5 Pinellas, Florida FL 47 Stable PM2.5 Portage, Ohio OH 40 Worsening Ozone Porter, Indiana IN 46 Improving PM2.5 Racine, Wisconsin WI 41 Stable Ozone Sandoval, New Mexico NM 44 Worsening Ozone Seminole, Florida FL 41 Worsening Ozone Sheboygan, Wisconsin WI 41 Stable Ozone Teton, Wyoming WY 43 Stable Ozone Washtenaw, Michigan MI 46 Stable PM2.5 West Baton Rouge, Louisiana LA 47 Stable PM2.5 Beaver, Pennsylvania PA 51 Stable PM2.5 Boise, Idaho ID 43 Stable PM2.5 Bradford, Pennsylvania PA 40 Worsening Ozone Burke, North Dakota ND 38 Worsening Ozone Campbell, Wyoming WY 44 Stable Ozone Canadian, Oklahoma OK 40 Worsening Ozone Cumberland, New Jersey NJ 42 Worsening Ozone Davidson, Tennessee TN 52 Stable PM2.5 Dougherty, Georgia GA 51 Stable PM2.5 Fairfax, Virginia VA 47 Stable PM2.5 Fairfield, Connecticut CT 46 Improving PM2.5 Fergus, Montana MT 40 Worsening Ozone Forsyth, North Carolina NC 49 Stable PM2.5 Fremont, Wyoming WY 46 Stable Ozone Gwinnett, Georgia GA 48 Stable PM2.5 Hidalgo, Texas TX 48 Stable PM2.5 Hillsborough, Florida FL 51 Stable PM2.5 Hinds, Mississippi MS 53 Stable PM2.5 Lee, North Carolina NC 52 Stable PM2.5 Lewis and Clark, Montana MT 44 Stable Ozone Middlesex, Massachusetts MA 39 Worsening Ozone Mobile, Alabama AL 49 Stable PM2.5 Olmsted, Minnesota MN 41 Worsening PM2.5 Pickens, South Carolina SC 44 Worsening Ozone Powder River, Montana MT 41 Worsening Ozone Randolph, Illinois IL 45 Stable PM2.5 Rio Blanco, Colorado CO 47 Stable Ozone San Miguel, Colorado CO 47 Worsening Ozone Santa Cruz, Arizona AZ 43 Worsening PM2.5 Snohomish, Washington WA 38 Stable PM2.5 Sublette, Wyoming WY 46 Stable Ozone Sweetwater, Wyoming WY 46 Stable Ozone Trego, Kansas KS 41 Worsening Ozone Volusia, Florida FL 44 Worsening PM2.5 Walker, Georgia GA 50 Stable PM2.5 Alameda, California CA 50 Improving PM2.5 Baltimore, Maryland MD 45 Stable Ozone Butte, California CA 52 Improving PM2.5 Carson City, Nevada NV 44 Stable Ozone Carter, Oklahoma OK 45 Worsening PM2.5 Cass, North Dakota ND 41 Worsening Ozone Christian, Kentucky KY 45 Worsening Ozone Collin, Texas TX 39 Worsening Ozone Contra Costa, California CA 48 Stable PM2.5 DeSoto, Mississippi MS 48 Stable PM2.5 Dodge, Wisconsin WI 44 Worsening Ozone El Dorado, California CA 43 Stable Ozone Essex, New Jersey NJ 45 Worsening PM2.5 Fairbanks North Star, Alaska AK 42 Improving PM2.5 Forrest, Mississippi MS 50 Stable PM2.5 Franklin, Ohio OH 50 Stable PM2.5 Grand, Colorado CO 46 Worsening Ozone Greenville, South Carolina SC 49 Stable PM2.5 Harrison, Mississippi MS 48 Stable PM2.5 Iberville, Louisiana LA 40 Worsening Ozone Kenosha, Wisconsin WI 45 Stable Ozone La Crosse, Wisconsin WI 42 Worsening PM2.5 Lycoming, Pennsylvania PA 40 Worsening Ozone Middlesex, New Jersey NJ 43 Worsening PM2.5 Nueces, Texas TX 47 Stable PM2.5 Oliver, North Dakota ND 39 Worsening Ozone Osage, Oklahoma OK 40 Worsening Ozone Outagamie, Wisconsin WI 43 Stable PM2.5 Peoria, Illinois IL 47 Stable PM2.5 Philadelphia, Pennsylvania PA 52 Improving PM2.5 Polk, Iowa IA 44 Stable PM2.5 San Juan, New Mexico NM 46 Stable Ozone Santa Clara, California CA 49 Stable PM2.5 St. Joseph, Indiana IN 50 Stable PM2.5 Union, Arkansas AR 47 Worsening PM2.5 Utah, Utah UT 48 Stable Ozone Yuma, Arizona AZ 48 Stable Ozone Albany, Wyoming WY 48 Stable Ozone Bay, Florida FL 47 Worsening PM2.5 Benewah, Idaho ID 48 Stable PM2.5 Bossier, Louisiana LA 47 Worsening PM2.5 Bowie, Texas TX 51 Stable PM2.5 Burleigh, North Dakota ND 38 Worsening PM2.5 Calcasieu, Louisiana LA 52 Stable PM2.5 Champaign, Illinois IL 45 Worsening PM2.5 Chippewa, Michigan MI 43 Worsening PM2.5 Clark, Indiana IN 50 Stable PM2.5 Clarke, Georgia GA 49 Worsening PM2.5 Durham, North Carolina NC 49 Worsening PM2.5 El Paso, Colorado CO 46 Stable Ozone Fulton, Georgia GA 53 Stable PM2.5 Holmes, Florida FL 48 Worsening PM2.5 Jefferson, Texas TX 48 Stable PM2.5 Kleberg, Texas TX 45 Worsening PM2.5 Lake, Indiana IN 53 Stable PM2.5 Lehigh, Pennsylvania PA 43 Worsening PM2.5 Love, Oklahoma OK 44 Worsening Ozone McLennan, Texas TX 43 Worsening Ozone Nez Perce, Idaho ID 33 Worsening PM2.5 Orange, California CA 54 Improving PM2.5 Ozaukee, Wisconsin WI 42 Worsening PM2.5 Pulaski, Arkansas AR 53 Stable PM2.5 Queens, New York NY 46 Stable PM2.5 Sauk, Wisconsin WI 42 Worsening PM2.5 Sequoyah, Oklahoma OK 41 Worsening PM2.5 Shelby, Tennessee TN 50 Stable PM2.5 Benton, Washington WA 38 Worsening PM2.5 Clear Creek, Colorado CO 48 Stable Ozone Colusa, California CA 47 Stable PM2.5 Crittenden, Arkansas AR 45 Worsening PM2.5 Dakota, Minnesota MN 40 Worsening PM2.5 Dane, Wisconsin WI 46 Worsening PM2.5 Gilpin, Colorado CO 46 Worsening Ozone Grant, Wisconsin WI 42 Worsening PM2.5 Hamilton, Ohio OH 55 Improving PM2.5 Harrison, Texas TX 46 Worsening PM2.5 Jefferson, Kentucky KY 54 Stable PM2.5 Johnson, Iowa IA 48 Worsening PM2.5 Kalamazoo, Michigan MI 47 Worsening PM2.5 Lincoln, Wyoming WY 29 Worsening PM10 Lyon, Minnesota MN 38 Worsening PM2.5 Macomb, Michigan MI 44 Worsening Ozone Madera, California CA 56 Improving Ozone Merced, California CA 54 Improving Ozone Missaukee, Michigan MI 43 Worsening Ozone Montgomery, Ohio OH 51 Stable PM2.5 Montgomery, Texas TX 48 Stable PM2.5 Ottawa, Michigan MI 44 Worsening Ozone Richmond City, Virginia VA 42 Worsening PM2.5 Richmond, Georgia GA 51 Worsening PM2.5 Sedgwick, Kansas KS 45 Worsening Ozone Shasta, California CA 44 Stable Ozone Stearns, Minnesota MN 39 Worsening PM2.5 Sutter, California CA 52 Improving PM2.5 Tehama, California CA 45 Stable Ozone Tooele, Utah UT 44 Worsening Ozone Washington, Oklahoma OK 47 Worsening PM2.5 Washoe, Nevada NV 50 Stable Ozone Wyandotte, Kansas KS 50 Stable PM2.5 Bell, Kentucky KY 45 Worsening Ozone Cache, Utah UT 47 Stable Ozone Citrus, Florida FL 43 Worsening PM2.5 Columbia, Florida FL 45 Worsening PM2.5 Eau Claire, Wisconsin WI 42 Worsening PM2.5 Escambia, Florida FL 49 Worsening PM2.5 Grant, Oklahoma OK 28 Worsening PM2.5 Hamilton, Illinois IL 46 Worsening PM2.5 Jackson, Oregon OR 44 Stable PM2.5 Jersey, Illinois IL 46 Worsening PM2.5 Linn, Iowa IA 49 Worsening PM2.5 Macon, Illinois IL 49 Worsening PM2.5 Park, Colorado CO 49 Worsening Ozone Pittsburg, Oklahoma OK 47 Worsening PM2.5 Tulsa, Oklahoma OK 51 Stable PM2.5 Washington, Arkansas AR 46 Worsening PM2.5 Will, Illinois IL 51 Stable PM2.5 Ada, Idaho ID 45 Worsening Ozone Baker, Florida FL 40 Worsening Ozone Becker, Minnesota MN 39 Worsening PM2.5 Bell, Texas TX 45 Worsening Ozone Dallas, Texas TX 50 Stable PM2.5 Del Norte, California CA 32 Worsening PM2.5 Galveston, Texas TX 45 Worsening Ozone Gila, Arizona AZ 46 Stable Ozone Hamilton, Tennessee TN 49 Worsening PM2.5 Jackson, Missouri MO 51 Worsening PM2.5 Lake, Illinois IL 40 Worsening Ozone Lancaster, Pennsylvania PA 55 Stable PM2.5 Milwaukee, Wisconsin WI 49 Worsening PM2.5 Stark, Ohio OH 51 Worsening PM2.5 Travis, Texas TX 52 Worsening PM2.5 Ward, North Dakota ND 36 Worsening Ozone Washington, Georgia GA 47 Worsening PM2.5 Waukesha, Wisconsin WI 48 Worsening PM2.5 Wright, Minnesota MN 41 Worsening PM2.5 Allegheny, Pennsylvania PA 56 Stable PM2.5 Arapahoe, Colorado CO 46 Stable Ozone Bannock, Idaho ID 37 Worsening PM2.5 Broward, Florida FL 49 Worsening PM2.5 Cameron, Texas TX 52 Worsening PM2.5 Cleveland, Oklahoma OK 51 Worsening PM2.5 Davis, Utah UT 46 Worsening Ozone Denton, Texas TX 46 Stable Ozone Duval, Florida FL 52 Worsening PM2.5 Garfield, Colorado CO 50 Worsening Ozone Grant, Oregon OR 45 Worsening PM2.5 Hancock, Mississippi MS 45 Worsening PM2.5 Horry, South Carolina SC 37 Worsening Ozone McClain, Oklahoma OK 44 Worsening Ozone McHenry, Illinois IL 49 Worsening PM2.5 Missoula, Montana MT 54 Improving PM2.5 Saint Clair, Illinois IL 50 Worsening PM2.5 Stevens, Washington WA 42 Worsening PM2.5 Adams, Colorado CO 50 Worsening Ozone Jefferson, Alabama AL 57 Stable PM2.5 Johnson, Kansas KS 44 Worsening Ozone Josephine, Oregon OR 38 Worsening PM2.5 Nevada, California CA 47 Stable Ozone Sacramento, California CA 53 Improving Ozone Scott, Minnesota MN 41 Worsening Ozone St. Louis City, Missouri MO 55 Stable PM2.5 Bonner, Idaho ID 33 Worsening PM2.5 Cass, Minnesota MN 32 Worsening PM2.5 Culberson, Texas TX 37 Worsening PM2.5 Denver, Colorado CO 54 Stable PM2.5 Duchesne, Utah UT 48 Worsening Ozone Idaho, Idaho ID 42 Worsening PM2.5 Kane, Illinois IL 43 Worsening Ozone Lane, Oregon OR 45 Stable PM2.5 Madison, Alabama AL 48 Worsening PM2.5 Mendocino, California CA 46 Worsening PM2.5 Ottawa, Oklahoma OK 51 Worsening PM2.5 Shawnee, Kansas KS 46 Worsening PM2.5 York, South Carolina SC 44 Worsening Ozone Archuleta, Colorado CO 39 Worsening Ozone Bexar, Texas TX 54 Stable PM2.5 Bolivar, Mississippi MS 47 Worsening PM2.5 Columbia, Washington WA 32 Worsening PM2.5 Cuyahoga, Ohio OH 56 Worsening PM2.5 Harney, Oregon OR 44 Worsening PM2.5 Lafourche, Louisiana LA 48 Worsening PM2.5 Larimer, Colorado CO 51 Stable Ozone Marion, Indiana IN 57 Stable PM2.5 Mariposa, California CA 49 Improving Ozone Okanogan, Washington WA 49 Worsening PM2.5 Oklahoma, Oklahoma OK 53 Worsening PM2.5 Trinity, California CA 32 Worsening PM2.5 Canyon, Idaho ID 41 Worsening PM2.5 Chaffee, Colorado CO 53 Worsening Ozone Delta, Colorado CO 42 Worsening Ozone Douglas, Oregon OR 36 Worsening PM2.5 Johnson, Wyoming WY 40 Worsening Ozone Klamath, Oregon OR 44 Stable PM2.5 Lincoln, Montana MT 52 Worsening PM2.5 Madison, Illinois IL 55 Worsening PM2.5 Pima, Arizona AZ 53 Worsening Ozone Sumner, Kansas KS 47 Worsening Ozone Wayne, Michigan MI 58 Stable PM2.5 Yakima, Washington WA 49 Worsening PM2.5
Frequently Asked Questions What does an Air Quality Grade C mean? Grade C (Average) indicates average air quality with regular moderate-to-unhealthy days for sensitive groups. The grade is based on 5-year average AQI (40%), trend direction (30%), unhealthy days per year (20%), and worst pollutant severity (10%).
How many US cities have Grade C air quality? 433 of 1,020 monitored US cities currently have a Grade C Air Quality rating, representing 42.5% of all tracked areas.
Is Grade C air quality safe? Grade C cities experience regular periods where air quality poses health risks, especially for children, the elderly, and people with respiratory conditions. Checking daily AQI readings is recommended.