Data sources
Everything on this site comes from public U.S. EPA data. We list each file so you can check our numbers against the original.
EPA AirData: Annual AQI by County
Publisher: U.S. Environmental Protection Agency, Air Quality System (AQS) / AirData. Downloaded from the AirData pre-generated files page. Background: EPA outdoor air quality data.
EPA notes that recent data may be revised as monitoring agencies certify it. The “EPA file date” below is the date stamped on the data file inside EPA’s download, which is the best available indicator of how current each file is.
| Year | File | County rows | EPA file date |
|---|---|---|---|
| 1980 | annual_aqi_by_county_1980.zip | 462 | 2026-06-26 |
| 1981 | annual_aqi_by_county_1981.zip | 484 | 2026-06-26 |
| 1982 | annual_aqi_by_county_1982.zip | 487 | 2026-06-26 |
| 1983 | annual_aqi_by_county_1983.zip | 494 | 2026-06-26 |
| 1984 | annual_aqi_by_county_1984.zip | 480 | 2026-06-26 |
| 1985 | annual_aqi_by_county_1985.zip | 549 | 2026-06-26 |
| 1986 | annual_aqi_by_county_1986.zip | 572 | 2026-06-26 |
| 1987 | annual_aqi_by_county_1987.zip | 616 | 2026-06-26 |
| 1988 | annual_aqi_by_county_1988.zip | 678 | 2026-06-26 |
| 1989 | annual_aqi_by_county_1989.zip | 741 | 2026-06-26 |
| 1990 | annual_aqi_by_county_1990.zip | 834 | 2026-06-26 |
| 1991 | annual_aqi_by_county_1991.zip | 878 | 2026-06-26 |
| 1992 | annual_aqi_by_county_1992.zip | 910 | 2026-06-26 |
| 1993 | annual_aqi_by_county_1993.zip | 929 | 2026-06-26 |
| 1994 | annual_aqi_by_county_1994.zip | 952 | 2026-06-26 |
| 1995 | annual_aqi_by_county_1995.zip | 984 | 2026-06-26 |
| 1996 | annual_aqi_by_county_1996.zip | 991 | 2026-06-26 |
| 1997 | annual_aqi_by_county_1997.zip | 1,013 | 2026-06-26 |
| 1998 | annual_aqi_by_county_1998.zip | 971 | 2026-06-26 |
| 1999 | annual_aqi_by_county_1999.zip | 1,045 | 2026-06-26 |
| 2000 | annual_aqi_by_county_2000.zip | 1,104 | 2026-06-26 |
| 2001 | annual_aqi_by_county_2001.zip | 1,121 | 2026-06-26 |
| 2002 | annual_aqi_by_county_2002.zip | 1,129 | 2026-06-26 |
| 2003 | annual_aqi_by_county_2003.zip | 1,136 | 2026-06-26 |
| 2004 | annual_aqi_by_county_2004.zip | 1,121 | 2026-06-26 |
| 2005 | annual_aqi_by_county_2005.zip | 1,114 | 2026-06-26 |
| 2006 | annual_aqi_by_county_2006.zip | 1,091 | 2026-06-26 |
| 2007 | annual_aqi_by_county_2007.zip | 1,082 | 2026-06-26 |
| 2008 | annual_aqi_by_county_2008.zip | 1,077 | 2026-06-26 |
| 2009 | annual_aqi_by_county_2009.zip | 1,077 | 2026-06-26 |
| 2010 | annual_aqi_by_county_2010.zip | 1,076 | 2026-06-26 |
| 2011 | annual_aqi_by_county_2011.zip | 1,071 | 2026-06-26 |
| 2012 | annual_aqi_by_county_2012.zip | 1,050 | 2026-06-26 |
| 2013 | annual_aqi_by_county_2013.zip | 1,044 | 2026-06-26 |
| 2014 | annual_aqi_by_county_2014.zip | 1,036 | 2026-06-26 |
| 2015 | annual_aqi_by_county_2015.zip | 1,042 | 2026-06-26 |
| 2016 | annual_aqi_by_county_2016.zip | 1,030 | 2026-06-26 |
| 2017 | annual_aqi_by_county_2017.zip | 1,029 | 2026-06-26 |
| 2018 | annual_aqi_by_county_2018.zip | 1,021 | 2026-06-26 |
| 2019 | annual_aqi_by_county_2019.zip | 1,023 | 2026-06-26 |
| 2020 | annual_aqi_by_county_2020.zip | 1,006 | 2026-06-26 |
| 2021 | annual_aqi_by_county_2021.zip | 1,005 | 2026-06-26 |
| 2022 | annual_aqi_by_county_2022.zip | 1,004 | 2026-06-26 |
| 2023 | annual_aqi_by_county_2023.zip | 993 | 2026-06-26 |
| 2024 | annual_aqi_by_county_2024.zip | 997 | 2026-06-26 |
| 2025 | annual_aqi_by_county_2025.zip | 985 | 2026-06-26 |
Rows that EPA files under “Country Of Mexico” or “Canada” (cross-border monitors) are not shown, since this site covers U.S. counties and territories.
Imported into EnviroNearby: November 5, 2026.