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

Wood County had the highest highest daily Air Quality Index (US EPA) of 17 counties in 2000, at 197. Summers County had the lowest, at 94. The median was 150. Source: the U.S. Environmental Protection Agency.

Keep it in a collection in your library.
Highest197Wood County
Median15017 counties

Map of counties, 2000

Berkeley County: 132 indexBrooke County: 145 indexCabell County: 150 indexGilmer County: 151 indexGreenbrier County: 154 indexHancock County: 150 indexHarrison County: 103 indexKanawha County: 159 indexMarion County: 110 indexMarshall County: 107 indexMercer County: 177 indexMonongalia County: 166 indexOhio County: 156 indexRaleigh County: 102 indexSummers County: 94 indexTucker County: 159 indexWood County: 197 index
  • Under 110
  • 110 to 150
  • 150 to 160
  • 160 and over
  • No data
index, 2000. 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, 2000

Wood County: 197 indexWood County197Mercer County: 177 indexMercer County177Monongalia County: 166 indexMonongalia County166Kanawha County: 159 indexKanawha County159Tucker County: 159 indexTucker County159Ohio County: 156 indexOhio County156Greenbrier County: 154 indexGreenbrier County154Gilmer County: 151 indexGilmer County151Cabell County: 150 indexCabell County150Hancock County: 150 indexHancock County150Brooke County: 145 indexBrooke County145Berkeley County: 132 indexBerkeley County132Marion County: 110 indexMarion County110Marshall County: 107 indexMarshall County107Harrison County: 103 indexHarrison County103Raleigh County: 102 indexRaleigh County102Summers County: 94 indexSummers County94Wood County: 197 indexWood County197Mercer County: 177 indexMercer County177Monongalia County: 166 indexMonongalia County166Kanawha County: 159 indexKanawha County159Tucker County: 159 indexTucker County159Ohio County: 156 indexOhio County156Greenbrier County: 154 indexGreenbrier County154Gilmer County: 151 indexGilmer County151Cabell County: 150 indexCabell County150Hancock County: 150 indexHancock County150Brooke County: 145 indexBrooke County145Berkeley County: 132 indexBerkeley County132Marion County: 110 indexMarion County110Marshall County: 107 indexMarshall County107Harrison County: 103 indexHarrison County103Raleigh County: 102 indexRaleigh County102Summers County: 94 indexSummers County94
index. Source: EPA, EPA AirData annual AQI by county: highest daily AQI. Retrieved 2026-10-12.

Full ranking

RankCounties2000
index
Change on 1999
1Wood County197-12
2Mercer County177n/a
3Monongalia County166+50
4Kanawha County159-55
4Tucker County159-26
6Ohio County156-21
7Greenbrier County154+3
8Gilmer County151-28
9Cabell County150-37
9Hancock County150-42
11Brooke County145-7
12Berkeley County132+2
13Marion County110n/a
14Marshall County107-31
15Harrison County103-31
16Raleigh County102-25
17Summers County94-16

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. 3 counties with data in other periods have no value for 2000 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 West Virginia by highest daily Air Quality Index (US EPA), 2000) [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 West Virginia by highest daily Air Quality Index (US EPA), 2000. 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/west-virginia-counties?period=2000. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Environmental Protection Agency. 2026. EPA AirData annual AQI by county: highest daily AQI. Counties in West Virginia by highest daily Air Quality Index (US EPA), 2000. 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/west-virginia-counties?period=2000.

Harvard

U.S. Environmental Protection Agency (2026) EPA AirData annual AQI by county: highest daily AQI, Counties in West Virginia by highest daily Air Quality Index (US EPA), 2000 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/rankings/highest-daily-air-quality-index/west-virginia-counties?period=2000 (Accessed: 12 October 2026).

BibTeX
@misc{environmental_counties_in_west_virginia_2000,
  author = {{U.S. Environmental Protection Agency}},
  title = {{EPA AirData annual AQI by county: highest daily AQI: Counties in West Virginia by highest daily Air Quality Index (US EPA), 2000}},
  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/west-virginia-counties?period=2000. 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 West Virginia by highest daily Air Quality Index (US EPA), 2000
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/west-virginia-counties?period=2000
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/highest-daily-air-quality-index/west-virginia-counties?period=2000.
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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Questions

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

Wood County, with 197 in 2000, according to the U.S. Environmental Protection Agency.

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

Summers County, with 94 in 2000.

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. 3 counties have no value for 2000 and are not ranked.

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

Counties in West Virginia: more rankings