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

Montgomery County had the highest highest daily Air Quality Index (US EPA) of 25 counties in 1998, at 216. Colbert County had the lowest, at 41. The median was 56. Source: the U.S. Environmental Protection Agency.

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Median5625 counties

Map of counties, 1998

Calhoun County: 51 indexClay County: 185 indexColbert County: 41 indexDeKalb County: 205 indexElmore County: 203 indexEscambia County: 58 indexEtowah County: 56 indexFranklin County: 42 indexGeneva County: 133 indexHouston County: 54 indexJefferson County: 212 indexLawrence County: 177 indexLimestone County: 43 indexMadison County: 200 indexMarengo County: 47 indexMobile County: 201 indexMontgomery County: 216 indexMorgan County: 49 indexPike County: 53 indexRussell County: 51 indexShelby County: 213 indexSumter County: 122 indexTalladega County: 51 indexTuscaloosa County: 49 indexWalker County: 50 index
  • Under 49
  • 49 to 52
  • 52 to 130
  • 130 to 200
  • 200 and over
  • No data
index, 1998. 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, 1998

Montgomery County: 216 indexMontgomery County216Shelby County: 213 indexShelby County213Jefferson County: 212 indexJefferson County212DeKalb County: 205 indexDeKalb County205Elmore County: 203 indexElmore County203Mobile County: 201 indexMobile County201Madison County: 200 indexMadison County200Clay County: 185 indexClay County185Lawrence County: 177 indexLawrence County177Geneva County: 133 indexGeneva County133Sumter County: 122 indexSumter County122Escambia County: 58 indexEscambia County58Etowah County: 56 indexEtowah County56Houston County: 54 indexHouston County54Pike County: 53 indexPike County53Calhoun County: 51 indexCalhoun County51Russell County: 51 indexRussell County51Talladega County: 51 indexTalladega County51Walker County: 50 indexWalker County50Morgan County: 49 indexMorgan County49Tuscaloosa County: 49 indexTuscaloosa County49Marengo County: 47 indexMarengo County47Limestone County: 43 indexLimestone County43Franklin County: 42 indexFranklin County42Colbert County: 41 indexColbert County41Montgomery County: 216 indexMontgomery County216Shelby County: 213 indexShelby County213Jefferson County: 212 indexJefferson County212DeKalb County: 205 indexDeKalb County205Elmore County: 203 indexElmore County203Mobile County: 201 indexMobile County201Madison County: 200 indexMadison County200Clay County: 185 indexClay County185Lawrence County: 177 indexLawrence County177Geneva County: 133 indexGeneva County133Sumter County: 122 indexSumter County122Escambia County: 58 indexEscambia County58Etowah County: 56 indexEtowah County56Houston County: 54 indexHouston County54Pike County: 53 indexPike County53Calhoun County: 51 indexCalhoun County51Russell County: 51 indexRussell County51Talladega County: 51 indexTalladega County51Walker County: 50 indexWalker County50Morgan County: 49 indexMorgan County49Tuscaloosa County: 49 indexTuscaloosa County49Marengo County: 47 indexMarengo County47Limestone County: 43 indexLimestone County43Franklin County: 42 indexFranklin County42Colbert County: 41 indexColbert County41
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. 6 counties with data in other periods have no value for 1998 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), 1998) [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), 1998. 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=1998. 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), 1998. 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=1998.

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), 1998 [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=1998 (Accessed: 12 October 2026).

BibTeX
@misc{environmental_counties_in_alabama_by_1998,
  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), 1998}},
  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=1998. 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), 1998
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=1998
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/highest-daily-air-quality-index/alabama-counties?period=1998.
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)?

Montgomery County, with 216 in 1998, according to the U.S. Environmental Protection Agency.

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

Colbert County, with 41 in 1998.

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. 6 counties have no value for 1998 and are not ranked.

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

Counties in Alabama: more rankings