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

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

Fairfax County had the highest median Air Quality Index (US EPA) of 41 counties in 1991, at 62. Newport News city had the lowest, at 13. The median was 38. Source: the U.S. Environmental Protection Agency.

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Highest62Fairfax County
Lowest13Newport News city
Median3841 counties

Map of counties, 1991

Amherst County: 49 indexArlington County: 47 indexAugusta County: 41 indexBuchanan County: 28 indexCampbell County: 18 indexCarroll County: 20 indexCharles City County: 45 indexChesterfield County: 42 indexFairfax County: 62 indexFauquier County: 58 indexGiles County: 47 indexHanover County: 54 indexHenrico County: 47 indexKing William County: 19 indexLoudoun County: 16 indexMadison County: 48 indexPrince Edward County: 40 indexPrince William County: 45 indexRoanoke County: 38 indexSmyth County: 22 indexWarren County: 42 indexWythe County: 50 indexYork County: 20 indexAlexandria city: 44 indexBristol city: 27 indexCharlottesville city: 25 indexChesapeake city: 22 indexCovington city: 28 indexFairfax city: 42 indexFredericksburg city: 19 indexHampton city: 45 indexHopewell city: 21 indexLynchburg city: 23 indexMartinsville city: 20 indexNewport News city: 13 indexNorfolk city: 37 indexPortsmouth city: 19 indexRichmond city: 39 indexRoanoke city: 31 indexSuffolk city: 49 indexWinchester city: 25 index
  • Under 20
  • 20 to 25
  • 25 to 38
  • 38 to 43
  • 43 to 47
  • 47 and over
  • No data
index, 1991. 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, 1991

Fairfax County: 62 indexFairfax County62Fauquier County: 58 indexFauquier County58Hanover County: 54 indexHanover County54Wythe County: 50 indexWythe County50Amherst County: 49 indexAmherst County49Suffolk city: 49 indexSuffolk city49Madison County: 48 indexMadison County48Arlington County: 47 indexArlington County47Giles County: 47 indexGiles County47Henrico County: 47 indexHenrico County47Charles City County: 45 indexCharles City County45Hampton city: 45 indexHampton city45Prince William County: 45 indexPrince William County45Alexandria city: 44 indexAlexandria city44Chesterfield County: 42 indexChesterfield County42Fairfax city: 42 indexFairfax city42Warren County: 42 indexWarren County42Augusta County: 41 indexAugusta County41Prince Edward County: 40 indexPrince Edward County40Richmond city: 39 indexRichmond city39Roanoke County: 38 indexRoanoke County38Norfolk city: 37 indexNorfolk city37Roanoke city: 31 indexRoanoke city31Buchanan County: 28 indexBuchanan County28Covington city: 28 indexCovington city28Bristol city: 27 indexBristol city27Charlottesville city: 25 indexCharlottesville city25Winchester city: 25 indexWinchester city25Lynchburg city: 23 indexLynchburg city23Chesapeake city: 22 indexChesapeake city22Smyth County: 22 indexSmyth County22Hopewell city: 21 indexHopewell city21Carroll County: 20 indexCarroll County20Martinsville city: 20 indexMartinsville city20York County: 20 indexYork County20Fredericksburg city: 19 indexFredericksburg city19King William County: 19 indexKing William County19Portsmouth city: 19 indexPortsmouth city19Campbell County: 18 indexCampbell County18Loudoun County: 16 indexLoudoun County16Newport News city: 13 indexNewport News city13Fairfax County: 62 indexFairfax County62Fauquier County: 58 indexFauquier County58Hanover County: 54 indexHanover County54Wythe County: 50 indexWythe County50Amherst County: 49 indexAmherst County49Suffolk city: 49 indexSuffolk city49Madison County: 48 indexMadison County48Arlington County: 47 indexArlington County47Giles County: 47 indexGiles County47Henrico County: 47 indexHenrico County47Charles City County: 45 indexCharles City County45Hampton city: 45 indexHampton city45Prince William County: 45 indexPrince William County45Alexandria city: 44 indexAlexandria city44Chesterfield County: 42 indexChesterfield County42Fairfax city: 42 indexFairfax city42Warren County: 42 indexWarren County42Augusta County: 41 indexAugusta County41Prince Edward County: 40 indexPrince Edward County40Richmond city: 39 indexRichmond city39Roanoke County: 38 indexRoanoke County38Norfolk city: 37 indexNorfolk city37Roanoke city: 31 indexRoanoke city31Buchanan County: 28 indexBuchanan County28Covington city: 28 indexCovington city28Bristol city: 27 indexBristol city27Charlottesville city: 25 indexCharlottesville city25Winchester city: 25 indexWinchester city25Lynchburg city: 23 indexLynchburg city23Chesapeake city: 22 indexChesapeake city22Smyth County: 22 indexSmyth County22Hopewell city: 21 indexHopewell city21Carroll County: 20 indexCarroll County20Martinsville city: 20 indexMartinsville city20York County: 20 indexYork County20Fredericksburg city: 19 indexFredericksburg city19King William County: 19 indexKing William County19Portsmouth city: 19 indexPortsmouth city19Campbell County: 18 indexCampbell County18Loudoun County: 16 indexLoudoun County16Newport News city: 13 indexNewport News city13
index. Source: EPA, EPA AirData annual AQI by county: median daily AQI. Retrieved 2026-10-12.

Full ranking

RankCounties1991
index		Change on 1990
1Fairfax County62+7
2Fauquier County58+13
3Hanover County54+8
4Wythe County50+2
5Amherst County49+2
5Suffolk city49-1
7Madison County48+2
8Arlington County47+2
8Giles County470
8Henrico County47+8
11Charles City County45-2
11Hampton city45+5
11Prince William County45+25
14Alexandria city44+1
15Chesterfield County42+1
15Fairfax city42+1
15Warren County42+2
18Augusta County41+2
19Prince Edward County40-1
20Richmond city39-1
21Roanoke County38-1
22Norfolk city37+3
23Roanoke city31-5
24Buchanan County28-2
24Covington city28-1
26Bristol city27-1
27Charlottesville city25+1
27Winchester city25+4
29Lynchburg city23+2
30Chesapeake city22-2
30Smyth County22-2
32Hopewell city21-4
33Carroll County20-1
33Martinsville city200
33York County200
36Fredericksburg city190
36King William County19-1
36Portsmouth city190
39Campbell County18-1
40Loudoun County16-3
41Newport News city13+2

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. 19 counties with data in other periods have no value for 1991 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 Virginia by median Air Quality Index (US EPA), 1991) [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 Virginia by median Air Quality Index (US EPA), 1991. 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/virginia-counties?period=1991. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Environmental Protection Agency. 2026. EPA AirData annual AQI by county: median daily AQI. Counties in Virginia by median Air Quality Index (US EPA), 1991. 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/virginia-counties?period=1991.

Harvard

U.S. Environmental Protection Agency (2026) EPA AirData annual AQI by county: median daily AQI, Counties in Virginia by median Air Quality Index (US EPA), 1991 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/rankings/median-air-quality-index/virginia-counties?period=1991 (Accessed: 12 October 2026).

BibTeX
@misc{environmental_counties_in_virginia_by_1991,
  author = {{U.S. Environmental Protection Agency}},
  title = {{EPA AirData annual AQI by county: median daily AQI: Counties in Virginia by median Air Quality Index (US EPA), 1991}},
  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/virginia-counties?period=1991. 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 Virginia by median Air Quality Index (US EPA), 1991
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/virginia-counties?period=1991
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/median-air-quality-index/virginia-counties?period=1991.
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 Virginia by median Air Quality Index (US EPA) using official data, and cite the source.
rank_places {"indicator":"aqi_median","level":"province","within":"Virginia","limit":10}
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Questions

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

Fairfax County, with 62 in 1991, according to the U.S. Environmental Protection Agency.

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

Newport News city, with 13 in 1991.

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. 19 counties have no value for 1991 and are not ranked.

Median Air Quality Index (US EPA): other rankings

Counties in Virginia: more rankings