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

Charlottesville city had the highest share of days with good air quality (US EPA AQI) of 42 counties in 1996, at 100%. Rockbridge County had the lowest, at 25.5%. The median was 84.6%. Source: EPA.

Keep it in a collection in your library.
Median84.642 counties

Map of counties, 1996

Arlington County: 66.4 %Caroline County: 73.5 %Carroll County: 98.4 %Charles City County: 69.7 %Chesterfield County: 63.7 %Culpeper County: 100 %Fairfax County: 62 %Fauquier County: 57.5 %Frederick County: 63.8 %Giles County: 71.1 %Hanover County: 64 %Henrico County: 63.4 %Henry County: 62.5 %King William County: 96.7 %Loudoun County: 96.6 %Madison County: 59.8 %Northumberland County: 100 %Prince Edward County: 75.8 %Prince William County: 77.9 %Roanoke County: 82.2 %Rockbridge County: 25.5 %Smyth County: 98.4 %Stafford County: 57.5 %Tazewell County: 96.7 %Warren County: 100 %Wise County: 96.7 %Wythe County: 54.2 %Alexandria city: 75.8 %Bristol city: 98.4 %Charlottesville city: 100 %Chesapeake city: 100 %Covington city: 98.1 %Fredericksburg city: 98.4 %Hampton city: 63.4 %Lynchburg city: 100 %Martinsville city: 100 %Newport News city: 100 %Norfolk city: 90.4 %Richmond city: 86.9 %Roanoke city: 96.6 %Suffolk city: 68.2 %Winchester city: 100 %
  • Under 63
  • 63 to 69
  • 69 to 85
  • 85 to 97
  • 97 to 100
  • 100 and over
  • No data
%, 1996. 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, 1996

Charlottesville city: 100 %Charlottesville city100Chesapeake city: 100 %Chesapeake city100Culpeper County: 100 %Culpeper County100Lynchburg city: 100 %Lynchburg city100Martinsville city: 100 %Martinsville city100Newport News city: 100 %Newport News city100Northumberland County: 100 %Northumberland County100Warren County: 100 %Warren County100Winchester city: 100 %Winchester city100Bristol city: 98.4 %Bristol city98.4Carroll County: 98.4 %Carroll County98.4Fredericksburg city: 98.4 %Fredericksburg city98.4Smyth County: 98.4 %Smyth County98.4Covington city: 98.1 %Covington city98.1King William County: 96.7 %King William County96.7Tazewell County: 96.7 %Tazewell County96.7Wise County: 96.7 %Wise County96.7Loudoun County: 96.6 %Loudoun County96.6Roanoke city: 96.6 %Roanoke city96.6Norfolk city: 90.4 %Norfolk city90.4Richmond city: 86.9 %Richmond city86.9Roanoke County: 82.2 %Roanoke County82.2Prince William County: 77.9 %Prince William County77.9Alexandria city: 75.8 %Alexandria city75.8Prince Edward County: 75.8 %Prince Edward County75.8Caroline County: 73.5 %Caroline County73.5Giles County: 71.1 %Giles County71.1Charles City County: 69.7 %Charles City County69.7Suffolk city: 68.2 %Suffolk city68.2Arlington County: 66.4 %Arlington County66.4Hanover County: 64 %Hanover County64Frederick County: 63.8 %Frederick County63.8Chesterfield County: 63.7 %Chesterfield County63.7Hampton city: 63.4 %Hampton city63.4Henrico County: 63.4 %Henrico County63.4Henry County: 62.5 %Henry County62.5Fairfax County: 62 %Fairfax County62Madison County: 59.8 %Madison County59.8Fauquier County: 57.5 %Fauquier County57.5Stafford County: 57.5 %Stafford County57.5Wythe County: 54.2 %Wythe County54.2Rockbridge County: 25.5 %Rockbridge County25.5Charlottesville city: 100 %Charlottesville city100Chesapeake city: 100 %Chesapeake city100Culpeper County: 100 %Culpeper County100Lynchburg city: 100 %Lynchburg city100Martinsville city: 100 %Martinsville city100Newport News city: 100 %Newport News city100Northumberland County: 100 %Northumberland County100Warren County: 100 %Warren County100Winchester city: 100 %Winchester city100Bristol city: 98.4 %Bristol city98.4Carroll County: 98.4 %Carroll County98.4Fredericksburg city: 98.4 %Fredericksburg city98.4Smyth County: 98.4 %Smyth County98.4Covington city: 98.1 %Covington city98.1King William County: 96.7 %King William County96.7Tazewell County: 96.7 %Tazewell County96.7Wise County: 96.7 %Wise County96.7Loudoun County: 96.6 %Loudoun County96.6Roanoke city: 96.6 %Roanoke city96.6Norfolk city: 90.4 %Norfolk city90.4Richmond city: 86.9 %Richmond city86.9Roanoke County: 82.2 %Roanoke County82.2Prince William County: 77.9 %Prince William County77.9Alexandria city: 75.8 %Alexandria city75.8Prince Edward County: 75.8 %Prince Edward County75.8Caroline County: 73.5 %Caroline County73.5Giles County: 71.1 %Giles County71.1Charles City County: 69.7 %Charles City County69.7Suffolk city: 68.2 %Suffolk city68.2Arlington County: 66.4 %Arlington County66.4Hanover County: 64 %Hanover County64Frederick County: 63.8 %Frederick County63.8Chesterfield County: 63.7 %Chesterfield County63.7Hampton city: 63.4 %Hampton city63.4Henrico County: 63.4 %Henrico County63.4Henry County: 62.5 %Henry County62.5Fairfax County: 62 %Fairfax County62Madison County: 59.8 %Madison County59.8Fauquier County: 57.5 %Fauquier County57.5Stafford County: 57.5 %Stafford County57.5Wythe County: 54.2 %Wythe County54.2Rockbridge County: 25.5 %Rockbridge County25.5
%. Source: Invokely calculation with data from EPA. Retrieved 2026-10-12.

Full ranking

RankCounties1996 (%)Change on 1995
1Charlottesville city100+1.6 pts
1Chesapeake city1000 pts
1Culpeper County1000 pts
1Lynchburg city100+1.7 pts
1Martinsville city100+5.1 pts
1Newport News city1000 pts
1Northumberland County1000 pts
1Warren County1000 pts
1Winchester city1000 pts
10Bristol city98.4+1.8 pts
10Carroll County98.4+0.1 pts
10Fredericksburg city98.4-1.6 pts
10Smyth County98.4+1.7 pts
14Covington city98.1-1.9 pts
15King William County96.7-3.3 pts
15Tazewell County96.7-3.3 pts
15Wise County96.7-1.7 pts
18Loudoun County96.6-3.4 pts
18Roanoke city96.6+1.1 pts
20Norfolk city90.4+3 pts
21Richmond city86.9+3.3 pts
22Roanoke County82.2+9.7 pts
23Prince William County77.9+4.7 pts
24Alexandria city75.8+10.6 pts
24Prince Edward County75.8+9.9 pts
26Caroline County73.5-2.5 pts
27Giles County71.1+16.4 pts
28Charles City County69.7-1.3 pts
29Suffolk city68.2+11.9 pts
30Arlington County66.4+1.2 pts
31Hanover County64+7.5 pts
32Frederick County63.8+4.6 pts
33Chesterfield County63.7-1.5 pts
34Hampton city63.4-4.2 pts
34Henrico County63.4-0.6 pts
36Henry County62.5+3.3 pts
37Fairfax County62+0.1 pts
38Madison County59.8+2.9 pts
39Fauquier County57.5-0.7 pts
39Stafford County57.5+6 pts
41Wythe County54.2+1.6 pts
42Rockbridge County25.5+2 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. 18 counties with data in other periods have no value for 1996 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), 1996) [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), 1996. 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=1996. 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), 1996. 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=1996.

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), 1996 [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=1996 (Accessed: 12 October 2026).

BibTeX
@misc{environmental_counties_in_virginia_by_1996,
  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), 1996}},
  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=1996. 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), 1996
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=1996
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/good-air-quality-days-share/virginia-counties?period=1996.
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)?

Charlottesville city, with 100% in 1996, according to EPA.

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

Rockbridge County, with 25.5% in 1996.

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. 18 counties have no value for 1996 and are not ranked.

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

Counties in Virginia: more rankings