Data / Rankings / Median Air Quality Index (US EPA) / Counties in West Virginia

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

Berkeley County had the highest median Air Quality Index (US EPA) of 17 counties in 2000, at 61. Brooke County had the lowest, at 29. The median was 55. Source: the U.S. Environmental Protection Agency.

Keep it in a collection in your library.
Highest61Berkeley County
Lowest29Brooke County
Median5517 counties

Map of counties, 2000

Berkeley County: 61 indexBrooke County: 29 indexCabell County: 55 indexGilmer County: 34 indexGreenbrier County: 48 indexHancock County: 44 indexHarrison County: 60 indexKanawha County: 58 indexMarion County: 61 indexMarshall County: 60 indexMercer County: 56 indexMonongalia County: 51 indexOhio County: 38 indexRaleigh County: 57 indexSummers County: 46 indexTucker County: 41 indexWood County: 56 index
  • Under 42
  • 42 to 49
  • 49 to 56
  • 56 to 60
  • 60 and over
  • No data
index, 2000. Hatched areas have no value for this period. Source: EPA, EPA AirData annual AQI by county: median daily AQI. Boundaries: U.S. Census Bureau cartographic boundary files.

All counties, 2000

Berkeley County: 61 indexBerkeley County61Marion County: 61 indexMarion County61Harrison County: 60 indexHarrison County60Marshall County: 60 indexMarshall County60Kanawha County: 58 indexKanawha County58Raleigh County: 57 indexRaleigh County57Mercer County: 56 indexMercer County56Wood County: 56 indexWood County56Cabell County: 55 indexCabell County55Monongalia County: 51 indexMonongalia County51Greenbrier County: 48 indexGreenbrier County48Summers County: 46 indexSummers County46Hancock County: 44 indexHancock County44Tucker County: 41 indexTucker County41Ohio County: 38 indexOhio County38Gilmer County: 34 indexGilmer County34Brooke County: 29 indexBrooke County29Berkeley County: 61 indexBerkeley County61Marion County: 61 indexMarion County61Harrison County: 60 indexHarrison County60Marshall County: 60 indexMarshall County60Kanawha County: 58 indexKanawha County58Raleigh County: 57 indexRaleigh County57Mercer County: 56 indexMercer County56Wood County: 56 indexWood County56Cabell County: 55 indexCabell County55Monongalia County: 51 indexMonongalia County51Greenbrier County: 48 indexGreenbrier County48Summers County: 46 indexSummers County46Hancock County: 44 indexHancock County44Tucker County: 41 indexTucker County41Ohio County: 38 indexOhio County38Gilmer County: 34 indexGilmer County34Brooke County: 29 indexBrooke County29
index. Source: EPA, EPA AirData annual AQI by county: median daily AQI. Retrieved 2026-10-12.

Full ranking

RankCounties2000
index		Change on 1999
1Berkeley County61+1
1Marion County61n/a
3Harrison County60+1
3Marshall County60-4
5Kanawha County580
6Raleigh County57+1
7Mercer County56n/a
7Wood County56-2
9Cabell County55-7
10Monongalia County51-6
11Greenbrier County48-13
12Summers County46-4
13Hancock County44-2
14Tucker County41-4
15Ohio County38-6
16Gilmer County34-8
17Brooke County29-1

Other periods

About this ranking

Median of the daily Air Quality Index (AQI) values of a US county over the days of the year with an AQI, from the EPA AirData annual summaries.

More on how it is measured
  • The daily county AQI is the highest AQI among the monitors and pollutants reported that day (ozone, PM2.5, PM10, carbon monoxide and nitrogen dioxide).
  • Lower is cleaner: 0 to 50 is good, 51 to 100 moderate and above 100 unhealthy for sensitive groups.

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: median 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: median daily AQI (Counties in West Virginia by median 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: median daily AQI, Counties in West Virginia by median 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/median-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: median daily AQI. Counties in West Virginia by median 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/median-air-quality-index/west-virginia-counties?period=2000.

Harvard

U.S. Environmental Protection Agency (2026) EPA AirData annual AQI by county: median daily AQI, Counties in West Virginia by median 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/median-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: median daily AQI: Counties in West Virginia by median 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/median-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: median 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: median daily AQI: Counties in West Virginia by median 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/median-air-quality-index/west-virginia-counties?period=2000
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/median-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: median daily AQI. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Retrieved 2026-10-12.
ER  -
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Rank Counties in West Virginia by median Air Quality Index (US EPA) using official data, and cite the source.
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Questions

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

Berkeley County, with 61 in 2000, according to the U.S. Environmental Protection Agency.

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

Brooke County, with 29 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: median daily AQI. Retrieved 2026-10-12. 3 counties have no value for 2000 and are not ranked.

Median Air Quality Index (US EPA): other rankings

Counties in West Virginia: more rankings