Counties in Virginia by share of days with good air quality (US EPA AQI)

Carroll County had the highest share of days with good air quality (US EPA AQI) of 43 counties in 1997, at 100%. Rockbridge County had the lowest, at 18.8%. The median was 82.5%. Source: EPA.

Keep it in a collection in your library.
Highest100Carroll County
Median82.543 counties

Map of counties, 1997

Arlington County: 61.8 %Caroline County: 70.8 %Carroll County: 100 %Charles City County: 65.8 %Chesterfield County: 54.9 %Culpeper County: 98.2 %Fairfax County: 65.5 %Fauquier County: 60.3 %Frederick County: 57.5 %Giles County: 65.2 %Hanover County: 50 %Henrico County: 62.3 %Henry County: 60.4 %King William County: 98.4 %Loudoun County: 100 %Madison County: 57.7 %Northumberland County: 98.3 %Prince Edward County: 70.8 %Prince William County: 76.9 %Roanoke County: 70.6 %Rockbridge County: 18.8 %Rockingham County: 94.7 %Smyth County: 98.4 %Stafford County: 58 %Tazewell County: 100 %Warren County: 98.4 %Wise County: 100 %Wythe County: 49.5 %Alexandria city: 68.8 %Bristol city: 98.4 %Charlottesville city: 100 %Chesapeake city: 96.2 %Covington city: 98.3 %Fredericksburg city: 98.4 %Hampton city: 57.3 %Lynchburg city: 98.3 %Martinsville city: 98 %Newport News city: 99.7 %Norfolk city: 87.9 %Richmond city: 82.5 %Roanoke city: 97.3 %Suffolk city: 50.6 %Winchester city: 98.3 %
  • Under 58
  • 58 to 66
  • 66 to 83
  • 83 to 98
  • 98 and over
  • No data
%, 1997. Hatched areas have no value for this period. Source: Invokely calculation with data from EPA. Boundaries: U.S. Census Bureau cartographic boundary files.

All counties, 1997

Carroll County: 100 %Carroll County100Charlottesville city: 100 %Charlottesville city100Loudoun County: 100 %Loudoun County100Tazewell County: 100 %Tazewell County100Wise County: 100 %Wise County100Newport News city: 99.7 %Newport News city99.7Bristol city: 98.4 %Bristol city98.4Fredericksburg city: 98.4 %Fredericksburg city98.4King William County: 98.4 %King William County98.4Smyth County: 98.4 %Smyth County98.4Warren County: 98.4 %Warren County98.4Covington city: 98.3 %Covington city98.3Lynchburg city: 98.3 %Lynchburg city98.3Northumberland County: 98.3 %Northumberland County98.3Winchester city: 98.3 %Winchester city98.3Culpeper County: 98.2 %Culpeper County98.2Martinsville city: 98 %Martinsville city98Roanoke city: 97.3 %Roanoke city97.3Chesapeake city: 96.2 %Chesapeake city96.2Rockingham County: 94.7 %Rockingham County94.7Norfolk city: 87.9 %Norfolk city87.9Richmond city: 82.5 %Richmond city82.5Prince William County: 76.9 %Prince William County76.9Caroline County: 70.8 %Caroline County70.8Prince Edward County: 70.8 %Prince Edward County70.8Roanoke County: 70.6 %Roanoke County70.6Alexandria city: 68.8 %Alexandria city68.8Charles City County: 65.8 %Charles City County65.8Fairfax County: 65.5 %Fairfax County65.5Giles County: 65.2 %Giles County65.2Henrico County: 62.3 %Henrico County62.3Arlington County: 61.8 %Arlington County61.8Henry County: 60.4 %Henry County60.4Fauquier County: 60.3 %Fauquier County60.3Stafford County: 58 %Stafford County58Madison County: 57.7 %Madison County57.7Frederick County: 57.5 %Frederick County57.5Hampton city: 57.3 %Hampton city57.3Chesterfield County: 54.9 %Chesterfield County54.9Suffolk city: 50.6 %Suffolk city50.6Hanover County: 50 %Hanover County50Wythe County: 49.5 %Wythe County49.5Rockbridge County: 18.8 %Rockbridge County18.8Carroll County: 100 %Carroll County100Charlottesville city: 100 %Charlottesville city100Loudoun County: 100 %Loudoun County100Tazewell County: 100 %Tazewell County100Wise County: 100 %Wise County100Newport News city: 99.7 %Newport News city99.7Bristol city: 98.4 %Bristol city98.4Fredericksburg city: 98.4 %Fredericksburg city98.4King William County: 98.4 %King William County98.4Smyth County: 98.4 %Smyth County98.4Warren County: 98.4 %Warren County98.4Covington city: 98.3 %Covington city98.3Lynchburg city: 98.3 %Lynchburg city98.3Northumberland County: 98.3 %Northumberland County98.3Winchester city: 98.3 %Winchester city98.3Culpeper County: 98.2 %Culpeper County98.2Martinsville city: 98 %Martinsville city98Roanoke city: 97.3 %Roanoke city97.3Chesapeake city: 96.2 %Chesapeake city96.2Rockingham County: 94.7 %Rockingham County94.7Norfolk city: 87.9 %Norfolk city87.9Richmond city: 82.5 %Richmond city82.5Prince William County: 76.9 %Prince William County76.9Caroline County: 70.8 %Caroline County70.8Prince Edward County: 70.8 %Prince Edward County70.8Roanoke County: 70.6 %Roanoke County70.6Alexandria city: 68.8 %Alexandria city68.8Charles City County: 65.8 %Charles City County65.8Fairfax County: 65.5 %Fairfax County65.5Giles County: 65.2 %Giles County65.2Henrico County: 62.3 %Henrico County62.3Arlington County: 61.8 %Arlington County61.8Henry County: 60.4 %Henry County60.4Fauquier County: 60.3 %Fauquier County60.3Stafford County: 58 %Stafford County58Madison County: 57.7 %Madison County57.7Frederick County: 57.5 %Frederick County57.5Hampton city: 57.3 %Hampton city57.3Chesterfield County: 54.9 %Chesterfield County54.9Suffolk city: 50.6 %Suffolk city50.6Hanover County: 50 %Hanover County50Wythe County: 49.5 %Wythe County49.5Rockbridge County: 18.8 %Rockbridge County18.8
%. Source: Invokely calculation with data from EPA. Retrieved 2026-10-12.

Full ranking

RankCounties1997 (%)Change on 1996
1Carroll County100+1.6 pts
1Charlottesville city1000 pts
1Loudoun County100+3.4 pts
1Tazewell County100+3.3 pts
1Wise County100+3.3 pts
6Newport News city99.7-0.3 pts
7Bristol city98.40 pts
7Fredericksburg city98.40 pts
7King William County98.4+1.7 pts
7Smyth County98.40 pts
7Warren County98.4-1.6 pts
12Covington city98.3+0.2 pts
12Lynchburg city98.3-1.7 pts
12Northumberland County98.3-1.7 pts
12Winchester city98.3-1.7 pts
16Culpeper County98.2-1.8 pts
17Martinsville city98-2 pts
18Roanoke city97.3+0.7 pts
19Chesapeake city96.2-3.8 pts
20Rockingham County94.7n/a
21Norfolk city87.9-2.5 pts
22Richmond city82.5-4.4 pts
23Prince William County76.9-1 pts
24Caroline County70.8-2.7 pts
24Prince Edward County70.8-5 pts
26Roanoke County70.6-11.6 pts
27Alexandria city68.8-7 pts
28Charles City County65.8-3.9 pts
29Fairfax County65.5+3.5 pts
30Giles County65.2-5.9 pts
31Henrico County62.3-1.1 pts
32Arlington County61.8-4.6 pts
33Henry County60.4-2.1 pts
34Fauquier County60.3+2.8 pts
35Stafford County58+0.5 pts
36Madison County57.7-2.1 pts
37Frederick County57.5-6.3 pts
38Hampton city57.3-6.1 pts
39Chesterfield County54.9-8.8 pts
40Suffolk city50.6-17.6 pts
41Hanover County50-14 pts
42Wythe County49.5-4.7 pts
43Rockbridge County18.8-6.7 pts

Other periods

About this ranking

Days with a daily Air Quality Index of 0 to 50 (good) as a percentage of the days of the year with an AQI in a US county. Calculated by Invokely from the day counts in the EPA AirData annual summaries; both counts are stored with each value.

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 1997 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: good days as a share of days with an AQI, calculated with stored counts. 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: good days as a share of days with an AQI, calculated with stored counts (Counties in Virginia by share of days with good air quality (US EPA AQI), 1997) [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: good days as a share of days with an AQI, calculated with stored counts, Counties in Virginia by share of days with good air quality (US EPA AQI), 1997. U.S. Environmental Protection Agency, 13 July 2026, https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Invokely, https://invokely.ai/rankings/good-air-quality-days-share/virginia-counties?period=1997. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Environmental Protection Agency. 2026. EPA AirData annual AQI by county: good days as a share of days with an AQI, calculated with stored counts. Counties in Virginia by share of days with good air quality (US EPA AQI), 1997. Dataset. Accessed October 12, 2026. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Also distributed by Invokely, https://invokely.ai/rankings/good-air-quality-days-share/virginia-counties?period=1997.

Harvard

U.S. Environmental Protection Agency (2026) EPA AirData annual AQI by county: good days as a share of days with an AQI, calculated with stored counts, Counties in Virginia by share of days with good air quality (US EPA AQI), 1997 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/rankings/good-air-quality-days-share/virginia-counties?period=1997 (Accessed: 12 October 2026).

BibTeX
@misc{environmental_counties_in_virginia_by_1997,
  author = {{U.S. Environmental Protection Agency}},
  title = {{EPA AirData annual AQI by county: good days as a share of days with an AQI, calculated with stored counts: Counties in Virginia by share of days with good air quality (US EPA AQI), 1997}},
  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/good-air-quality-days-share/virginia-counties?period=1997. Publisher attribution: U.S. Environmental Protection Agency, Air Quality System, AirData. EPA AirData annual AQI by county: good days as a share of days with an AQI, calculated with stored counts. 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: good days as a share of days with an AQI, calculated with stored counts: Counties in Virginia by share of days with good air quality (US EPA AQI), 1997
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/good-air-quality-days-share/virginia-counties?period=1997
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/good-air-quality-days-share/virginia-counties?period=1997.
N1  - Publisher attribution: U.S. Environmental Protection Agency, Air Quality System, AirData. EPA AirData annual AQI by county: good days as a share of days with an AQI, calculated with stored counts. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Retrieved 2026-10-12.
ER  - 
Embed this chart

Paste this code into a web page or a blog post. The chart shows the latest figures as they are published, with the source and a link back to this page.

Sites that read oEmbed links, such as WordPress, can show the chart when you paste the link to this page.

Use this data in your AI agent

Invokely serves this figure to AI assistants through MCP and to code through a REST API, with the source and citation attached. Ask your assistant:

Rank Counties in Virginia by share of days with good air quality (US EPA AQI) using official data, and cite the source.
rank_places {"indicator":"aqi_good_days_share","level":"province","within":"Virginia","limit":10}
GET https://invokely.ai/api/v1/rank?indicator=aqi_good_days_share&level=province&within=Virginia&limit=10

Connect Claude, ChatGPT or Cursor in one step. The trial answers 25 calls a day without an account.

Questions

Which county has the highest share of days with good air quality (US EPA AQI)?

Carroll County, with 100% in 1997, according to EPA.

Which county has the lowest share of days with good air quality (US EPA AQI)?

Rockbridge County, with 18.8% in 1997.

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: good days as a share of days with an AQI, calculated with stored counts. Retrieved 2026-10-12. 17 counties have no value for 1997 and are not ranked.

Share of days with good air quality (US EPA AQI): other rankings

Counties in Virginia: more rankings