Counties in Alabama by highest daily Air Quality Index (US EPA)

Madison County had the highest highest daily Air Quality Index (US EPA) of 24 counties in 1993, at 215. Marengo County had the lowest, at 51. The median was 74. Source: the U.S. Environmental Protection Agency.

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Highest215Madison County
Median7424 counties

Map of counties, 1993

Calhoun County: 68 indexClay County: 164 indexColbert County: 51 indexDeKalb County: 177 indexElmore County: 156 indexEscambia County: 79 indexEtowah County: 67 indexFranklin County: 53 indexHouston County: 55 indexJackson County: 51 indexJefferson County: 205 indexLawrence County: 161 indexMadison County: 215 indexMarengo County: 51 indexMobile County: 115 indexMontgomery County: 174 indexMorgan County: 192 indexPike County: 59 indexRussell County: 60 indexShelby County: 209 indexSumter County: 100 indexTalladega County: 61 indexTuscaloosa County: 57 indexWalker County: 58 index
  • Under 56
  • 56 to 62
  • 62 to 110
  • 110 to 180
  • 180 and over
  • No data
index, 1993. Hatched areas have no value for this period. Source: EPA, EPA AirData annual AQI by county: highest daily AQI. Boundaries: U.S. Census Bureau cartographic boundary files.

All counties, 1993

Madison County: 215 indexMadison County215Shelby County: 209 indexShelby County209Jefferson County: 205 indexJefferson County205Morgan County: 192 indexMorgan County192DeKalb County: 177 indexDeKalb County177Montgomery County: 174 indexMontgomery County174Clay County: 164 indexClay County164Lawrence County: 161 indexLawrence County161Elmore County: 156 indexElmore County156Mobile County: 115 indexMobile County115Sumter County: 100 indexSumter County100Escambia County: 79 indexEscambia County79Calhoun County: 68 indexCalhoun County68Etowah County: 67 indexEtowah County67Talladega County: 61 indexTalladega County61Russell County: 60 indexRussell County60Pike County: 59 indexPike County59Walker County: 58 indexWalker County58Tuscaloosa County: 57 indexTuscaloosa County57Houston County: 55 indexHouston County55Franklin County: 53 indexFranklin County53Colbert County: 51 indexColbert County51Jackson County: 51 indexJackson County51Marengo County: 51 indexMarengo County51Madison County: 215 indexMadison County215Shelby County: 209 indexShelby County209Jefferson County: 205 indexJefferson County205Morgan County: 192 indexMorgan County192DeKalb County: 177 indexDeKalb County177Montgomery County: 174 indexMontgomery County174Clay County: 164 indexClay County164Lawrence County: 161 indexLawrence County161Elmore County: 156 indexElmore County156Mobile County: 115 indexMobile County115Sumter County: 100 indexSumter County100Escambia County: 79 indexEscambia County79Calhoun County: 68 indexCalhoun County68Etowah County: 67 indexEtowah County67Talladega County: 61 indexTalladega County61Russell County: 60 indexRussell County60Pike County: 59 indexPike County59Walker County: 58 indexWalker County58Tuscaloosa County: 57 indexTuscaloosa County57Houston County: 55 indexHouston County55Franklin County: 53 indexFranklin County53Colbert County: 51 indexColbert County51Jackson County: 51 indexJackson County51Marengo County: 51 indexMarengo County51
index. Source: EPA, EPA AirData annual AQI by county: highest daily AQI. Retrieved 2026-10-12.

Full ranking

Other periods

About this ranking

Highest daily Air Quality Index (AQI) value recorded in a US county during the year, from the EPA AirData annual summaries. Values above 500 are beyond the AQI scale and are published as EPA computes them.

A single day decides the value, so one wildfire or dust event can set it. Dust from the dry Owens Lake bed puts Inyo and Mono counties in California in the thousands. United States counties with air quality monitors only, about 1,000 of some 3,100 in recent years; a county without monitors has no value. The number of days with an AQI differs between counties because some monitors run only in the ozone season.

Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. 7 counties with data in other periods have no value for 1993 and are left out rather than filled from another source. Equal values share a rank.

How to cite

U.S. Environmental Protection Agency, Air Quality System, AirData. EPA AirData annual AQI by county: highest daily AQI. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Retrieved 2026-10-12.

Citation styles

The publisher is the author. Invokely is named only as the place the figures were read, where a style asks for it.

APA 7

U.S. Environmental Protection Agency. (2026). EPA AirData annual AQI by county: highest daily AQI (Counties in Alabama by highest daily Air Quality Index (US EPA), 1993) [Data set]. Retrieved October 12, 2026, from https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual

MLA 9

EPA AirData annual AQI by county: highest daily AQI, Counties in Alabama by highest daily Air Quality Index (US EPA), 1993. U.S. Environmental Protection Agency, 13 July 2026, https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Invokely, https://invokely.ai/rankings/highest-daily-air-quality-index/alabama-counties?period=1993. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Environmental Protection Agency. 2026. EPA AirData annual AQI by county: highest daily AQI. Counties in Alabama by highest daily Air Quality Index (US EPA), 1993. Dataset. Accessed October 12, 2026. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Also distributed by Invokely, https://invokely.ai/rankings/highest-daily-air-quality-index/alabama-counties?period=1993.

Harvard

U.S. Environmental Protection Agency (2026) EPA AirData annual AQI by county: highest daily AQI, Counties in Alabama by highest daily Air Quality Index (US EPA), 1993 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/rankings/highest-daily-air-quality-index/alabama-counties?period=1993 (Accessed: 12 October 2026).

BibTeX
@misc{environmental_counties_in_alabama_by_1993,
  author = {{U.S. Environmental Protection Agency}},
  title = {{EPA AirData annual AQI by county: highest daily AQI: Counties in Alabama by highest daily Air Quality Index (US EPA), 1993}},
  year = {2026},
  howpublished = {Data set},
  url = {https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual},
  urldate = {2026-10-12},
  note = {Accessed via Invokely, https://invokely.ai/rankings/highest-daily-air-quality-index/alabama-counties?period=1993. Publisher attribution: U.S. Environmental Protection Agency, Air Quality System, AirData. EPA AirData annual AQI by county: highest daily AQI. https://aqs.epa.gov/aqsweb/airdata/download\_files.html\#Annual. Retrieved 2026-10-12.},
}
RIS
TY  - DATA
AU  - U.S. Environmental Protection Agency
TI  - EPA AirData annual AQI by county: highest daily AQI: Counties in Alabama by highest daily Air Quality Index (US EPA), 1993
PY  - 2026
DA  - 2026/07/13
PB  - U.S. Environmental Protection Agency
DB  - Invokely
UR  - https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual
L2  - https://invokely.ai/rankings/highest-daily-air-quality-index/alabama-counties?period=1993
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/highest-daily-air-quality-index/alabama-counties?period=1993.
N1  - Publisher attribution: U.S. Environmental Protection Agency, Air Quality System, AirData. EPA AirData annual AQI by county: highest daily AQI. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Retrieved 2026-10-12.
ER  - 
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Rank Counties in Alabama by highest daily Air Quality Index (US EPA) using official data, and cite the source.
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Questions

Which county has the highest highest daily Air Quality Index (US EPA)?

Madison County, with 215 in 1993, according to the U.S. Environmental Protection Agency.

Which county has the lowest highest daily Air Quality Index (US EPA)?

Marengo County, with 51 in 1993.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: U.S. Environmental Protection Agency, EPA AirData annual AQI by county: highest daily AQI. Retrieved 2026-10-12. 7 counties have no value for 1993 and are not ranked.

Highest daily Air Quality Index (US EPA): other rankings

Counties in Alabama: more rankings