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

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

Suffolk city had the highest highest daily Air Quality Index (US EPA) of 43 counties in 1992, at 217. Loudoun County had the lowest, at 34. The median was 101. Source: the U.S. Environmental Protection Agency.

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Highest217Suffolk city
Lowest34Loudoun County
Median10143 counties

Map of counties, 1992

Amherst County: 151 indexArlington County: 177 indexAugusta County: 166 indexBuchanan County: 39 indexCampbell County: 36 indexCarroll County: 51 indexCharles City County: 195 indexChesterfield County: 182 indexCulpeper County: 40 indexFairfax County: 192 indexFauquier County: 166 indexFrederick County: 159 indexGiles County: 156 indexHanover County: 190 indexHenrico County: 197 indexKing William County: 49 indexLoudoun County: 34 indexMadison County: 174 indexNorthumberland County: 54 indexPrince Edward County: 164 indexPrince William County: 179 indexRoanoke County: 140 indexSmyth County: 57 indexStafford County: 93 indexWarren County: 159 indexWythe County: 136 indexYork County: 48 indexAlexandria city: 161 indexBristol city: 47 indexCharlottesville city: 35 indexChesapeake city: 50 indexCovington city: 52 indexFairfax city: 67 indexFredericksburg city: 39 indexHampton city: 206 indexLynchburg city: 46 indexMartinsville city: 46 indexNewport News city: 48 indexNorfolk city: 106 indexRichmond city: 101 indexRoanoke city: 63 indexSuffolk city: 217 indexWinchester city: 37 index
  • Under 46
  • 46 to 51
  • 51 to 100
  • 100 to 160
  • 160 to 180
  • 180 and over
  • No data
index, 1992. 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, 1992

Suffolk city: 217 indexSuffolk city217Hampton city: 206 indexHampton city206Henrico County: 197 indexHenrico County197Charles City County: 195 indexCharles City County195Fairfax County: 192 indexFairfax County192Hanover County: 190 indexHanover County190Chesterfield County: 182 indexChesterfield County182Prince William County: 179 indexPrince William County179Arlington County: 177 indexArlington County177Madison County: 174 indexMadison County174Augusta County: 166 indexAugusta County166Fauquier County: 166 indexFauquier County166Prince Edward County: 164 indexPrince Edward County164Alexandria city: 161 indexAlexandria city161Frederick County: 159 indexFrederick County159Warren County: 159 indexWarren County159Giles County: 156 indexGiles County156Amherst County: 151 indexAmherst County151Roanoke County: 140 indexRoanoke County140Wythe County: 136 indexWythe County136Norfolk city: 106 indexNorfolk city106Richmond city: 101 indexRichmond city101Stafford County: 93 indexStafford County93Fairfax city: 67 indexFairfax city67Roanoke city: 63 indexRoanoke city63Smyth County: 57 indexSmyth County57Northumberland County: 54 indexNorthumberland County54Covington city: 52 indexCovington city52Carroll County: 51 indexCarroll County51Chesapeake city: 50 indexChesapeake city50King William County: 49 indexKing William County49Newport News city: 48 indexNewport News city48York County: 48 indexYork County48Bristol city: 47 indexBristol city47Lynchburg city: 46 indexLynchburg city46Martinsville city: 46 indexMartinsville city46Culpeper County: 40 indexCulpeper County40Buchanan County: 39 indexBuchanan County39Fredericksburg city: 39 indexFredericksburg city39Winchester city: 37 indexWinchester city37Campbell County: 36 indexCampbell County36Charlottesville city: 35 indexCharlottesville city35Loudoun County: 34 indexLoudoun County34Suffolk city: 217 indexSuffolk city217Hampton city: 206 indexHampton city206Henrico County: 197 indexHenrico County197Charles City County: 195 indexCharles City County195Fairfax County: 192 indexFairfax County192Hanover County: 190 indexHanover County190Chesterfield County: 182 indexChesterfield County182Prince William County: 179 indexPrince William County179Arlington County: 177 indexArlington County177Madison County: 174 indexMadison County174Augusta County: 166 indexAugusta County166Fauquier County: 166 indexFauquier County166Prince Edward County: 164 indexPrince Edward County164Alexandria city: 161 indexAlexandria city161Frederick County: 159 indexFrederick County159Warren County: 159 indexWarren County159Giles County: 156 indexGiles County156Amherst County: 151 indexAmherst County151Roanoke County: 140 indexRoanoke County140Wythe County: 136 indexWythe County136Norfolk city: 106 indexNorfolk city106Richmond city: 101 indexRichmond city101Stafford County: 93 indexStafford County93Fairfax city: 67 indexFairfax city67Roanoke city: 63 indexRoanoke city63Smyth County: 57 indexSmyth County57Northumberland County: 54 indexNorthumberland County54Covington city: 52 indexCovington city52Carroll County: 51 indexCarroll County51Chesapeake city: 50 indexChesapeake city50King William County: 49 indexKing William County49Newport News city: 48 indexNewport News city48York County: 48 indexYork County48Bristol city: 47 indexBristol city47Lynchburg city: 46 indexLynchburg city46Martinsville city: 46 indexMartinsville city46Culpeper County: 40 indexCulpeper County40Buchanan County: 39 indexBuchanan County39Fredericksburg city: 39 indexFredericksburg city39Winchester city: 37 indexWinchester city37Campbell County: 36 indexCampbell County36Charlottesville city: 35 indexCharlottesville city35Loudoun County: 34 indexLoudoun County34
index. Source: EPA, EPA AirData annual AQI by county: highest daily AQI. Retrieved 2026-10-12.

Full ranking

RankCounties1992
index		Change on 1991
1Suffolk city217+56
2Hampton city206+34
3Henrico County197+5
4Charles City County195+18
5Fairfax County192-51
6Hanover County190+24
7Chesterfield County182+26
8Prince William County1790
9Arlington County177-47
10Madison County174+10
11Augusta County166+19
11Fauquier County166-11
13Prince Edward County164+10
14Alexandria city161-45
15Frederick County159n/a
15Warren County159-18
17Giles County156-10
18Amherst County1510
19Roanoke County140-14
20Wythe County136-11
21Norfolk city106+5
22Richmond city1010
23Stafford County93n/a
24Fairfax city67-138
25Roanoke city63+2
26Smyth County57-12
27Northumberland County54n/a
28Covington city52-51
29Carroll County51-12
30Chesapeake city50-2
31King William County49-8
32Newport News city48-1
32York County48-4
34Bristol city47-13
35Lynchburg city46-22
35Martinsville city46-1
37Culpeper County40n/a
38Buchanan County39-107
38Fredericksburg city39-16
40Winchester city37-16
41Campbell County36-15
42Charlottesville city35-17
43Loudoun County34-15

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. 17 counties with data in other periods have no value for 1992 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), 1992) [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), 1992. 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=1992. 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), 1992. 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=1992.

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), 1992 [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=1992 (Accessed: 12 October 2026).

BibTeX
@misc{environmental_counties_in_virginia_by_1992,
  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), 1992}},
  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=1992. 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), 1992
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=1992
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/highest-daily-air-quality-index/virginia-counties?period=1992.
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.
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Questions

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

Suffolk city, with 217 in 1992, according to the U.S. Environmental Protection Agency.

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

Loudoun County, with 34 in 1992.

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. 17 counties have no value for 1992 and are not ranked.

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

Counties in Virginia: more rankings