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

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

Fairfax County had the highest highest daily Air Quality Index (US EPA) of 42 counties in 1990, at 212. Campbell County had the lowest, at 40. The median was 92. Source: the U.S. Environmental Protection Agency.

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Highest212Fairfax County
Lowest40Campbell County
Median9242 counties

Map of counties, 1990

Amherst County: 151 indexArlington County: 208 indexAugusta County: 151 indexBuchanan County: 78 indexCampbell County: 40 indexCarroll County: 53 indexCharles City County: 202 indexChesterfield County: 187 indexFairfax County: 212 indexFauquier County: 164 indexGiles County: 161 indexHanover County: 159 indexHenrico County: 200 indexKing William County: 52 indexLoudoun County: 57 indexMadison County: 169 indexNorthampton County: 207 indexPrince Edward County: 172 indexPrince William County: 41 indexRoanoke County: 129 indexSmyth County: 53 indexWarren County: 159 indexWythe County: 164 indexYork County: 53 indexAlexandria city: 185 indexBristol city: 55 indexCharlottesville city: 60 indexChesapeake city: 49 indexCovington city: 59 indexFairfax city: 200 indexFredericksburg city: 61 indexHampton city: 159 indexHopewell city: 59 indexLynchburg city: 49 indexMartinsville city: 45 indexNewport News city: 45 indexNorfolk city: 82 indexPortsmouth city: 52 indexRichmond city: 102 indexRoanoke city: 62 indexSuffolk city: 182 indexWinchester city: 61 index
  • Under 52
  • 52 to 59
  • 59 to 92
  • 92 to 160
  • 160 to 190
  • 190 and over
  • No data
index, 1990. 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, 1990

Fairfax County: 212 indexFairfax County212Arlington County: 208 indexArlington County208Northampton County: 207 indexNorthampton County207Charles City County: 202 indexCharles City County202Fairfax city: 200 indexFairfax city200Henrico County: 200 indexHenrico County200Chesterfield County: 187 indexChesterfield County187Alexandria city: 185 indexAlexandria city185Suffolk city: 182 indexSuffolk city182Prince Edward County: 172 indexPrince Edward County172Madison County: 169 indexMadison County169Fauquier County: 164 indexFauquier County164Wythe County: 164 indexWythe County164Giles County: 161 indexGiles County161Hampton city: 159 indexHampton city159Hanover County: 159 indexHanover County159Warren County: 159 indexWarren County159Amherst County: 151 indexAmherst County151Augusta County: 151 indexAugusta County151Roanoke County: 129 indexRoanoke County129Richmond city: 102 indexRichmond city102Norfolk city: 82 indexNorfolk city82Buchanan County: 78 indexBuchanan County78Roanoke city: 62 indexRoanoke city62Fredericksburg city: 61 indexFredericksburg city61Winchester city: 61 indexWinchester city61Charlottesville city: 60 indexCharlottesville city60Covington city: 59 indexCovington city59Hopewell city: 59 indexHopewell city59Loudoun County: 57 indexLoudoun County57Bristol city: 55 indexBristol city55Carroll County: 53 indexCarroll County53Smyth County: 53 indexSmyth County53York County: 53 indexYork County53King William County: 52 indexKing William County52Portsmouth city: 52 indexPortsmouth city52Chesapeake city: 49 indexChesapeake city49Lynchburg city: 49 indexLynchburg city49Martinsville city: 45 indexMartinsville city45Newport News city: 45 indexNewport News city45Prince William County: 41 indexPrince William County41Campbell County: 40 indexCampbell County40Fairfax County: 212 indexFairfax County212Arlington County: 208 indexArlington County208Northampton County: 207 indexNorthampton County207Charles City County: 202 indexCharles City County202Fairfax city: 200 indexFairfax city200Henrico County: 200 indexHenrico County200Chesterfield County: 187 indexChesterfield County187Alexandria city: 185 indexAlexandria city185Suffolk city: 182 indexSuffolk city182Prince Edward County: 172 indexPrince Edward County172Madison County: 169 indexMadison County169Fauquier County: 164 indexFauquier County164Wythe County: 164 indexWythe County164Giles County: 161 indexGiles County161Hampton city: 159 indexHampton city159Hanover County: 159 indexHanover County159Warren County: 159 indexWarren County159Amherst County: 151 indexAmherst County151Augusta County: 151 indexAugusta County151Roanoke County: 129 indexRoanoke County129Richmond city: 102 indexRichmond city102Norfolk city: 82 indexNorfolk city82Buchanan County: 78 indexBuchanan County78Roanoke city: 62 indexRoanoke city62Fredericksburg city: 61 indexFredericksburg city61Winchester city: 61 indexWinchester city61Charlottesville city: 60 indexCharlottesville city60Covington city: 59 indexCovington city59Hopewell city: 59 indexHopewell city59Loudoun County: 57 indexLoudoun County57Bristol city: 55 indexBristol city55Carroll County: 53 indexCarroll County53Smyth County: 53 indexSmyth County53York County: 53 indexYork County53King William County: 52 indexKing William County52Portsmouth city: 52 indexPortsmouth city52Chesapeake city: 49 indexChesapeake city49Lynchburg city: 49 indexLynchburg city49Martinsville city: 45 indexMartinsville city45Newport News city: 45 indexNewport News city45Prince William County: 41 indexPrince William County41Campbell County: 40 indexCampbell County40
index. Source: EPA, EPA AirData annual AQI by county: highest daily AQI. Retrieved 2026-10-12.

Full ranking

RankCounties1990
index		Change on 1989
1Fairfax County212-5
2Arlington County208+18
3Northampton County207+48
4Charles City County202+76
5Fairfax city200-2
5Henrico County200+23
7Chesterfield County187+23
8Alexandria city185-5
9Suffolk city1820
10Prince Edward County172n/a
11Madison County169+43
12Fauquier County164-2
12Wythe County164n/a
14Giles County161n/a
15Hampton city159-7
15Hanover County159-15
15Warren County159-13
18Amherst County151n/a
18Augusta County151+25
20Roanoke County129-4
21Richmond city102+8
22Norfolk city82-16
23Buchanan County78-8
24Roanoke city62+2
25Fredericksburg city61+18
25Winchester city61+8
27Charlottesville city60+5
28Covington city59+7
28Hopewell city59+2
30Loudoun County57n/a
31Bristol city55+1
32Carroll County53-4
32Smyth County53-97
32York County53+16
35King William County52n/a
35Portsmouth city52+5
37Chesapeake city49-5
37Lynchburg city49-3
39Martinsville city45-19
39Newport News city45-4
41Prince William County41n/a
42Campbell County40-7

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. 18 counties with data in other periods have no value for 1990 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 Virginia by highest daily Air Quality Index (US EPA), 1990) [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 Virginia by highest daily Air Quality Index (US EPA), 1990. 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/virginia-counties?period=1990. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Environmental Protection Agency. 2026. EPA AirData annual AQI by county: highest daily AQI. Counties in Virginia by highest daily Air Quality Index (US EPA), 1990. 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/virginia-counties?period=1990.

Harvard

U.S. Environmental Protection Agency (2026) EPA AirData annual AQI by county: highest daily AQI, Counties in Virginia by highest daily Air Quality Index (US EPA), 1990 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/rankings/highest-daily-air-quality-index/virginia-counties?period=1990 (Accessed: 12 October 2026).

BibTeX
@misc{environmental_counties_in_virginia_by_1990,
  author = {{U.S. Environmental Protection Agency}},
  title = {{EPA AirData annual AQI by county: highest daily AQI: Counties in Virginia by highest daily Air Quality Index (US EPA), 1990}},
  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/virginia-counties?period=1990. 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 Virginia by highest daily Air Quality Index (US EPA), 1990
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/virginia-counties?period=1990
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/highest-daily-air-quality-index/virginia-counties?period=1990.
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 Virginia by highest daily Air Quality Index (US EPA) using official data, and cite the source.
rank_places {"indicator":"aqi_max","level":"province","within":"Virginia","limit":10}
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Questions

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

Fairfax County, with 212 in 1990, according to the U.S. Environmental Protection Agency.

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

Campbell County, with 40 in 1990.

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. 18 counties have no value for 1990 and are not ranked.

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

Counties in Virginia: more rankings