Highest daily Air Quality Index (US EPA) in King William County

Highest daily Air Quality Index (US EPA) in King William County was 20 in 2016, according to the U.S. Environmental Protection Agency. That is down 10 from 2015.

2016, index20

Change on 2015-10

Series high1002011

Series low202004

Next release: Tuesday, 13 July 2027, estimated by Invokely from past publication dates (low confidence), not announced by the publisher. Release calendar

Highest daily Air Quality Index (US EPA) in King William County, 1990 to 2016

index. Source: EPA, EPA AirData annual AQI by county: highest daily AQI. Retrieved 2026-10-12, published 2026-07-13.

All 27 values

Period	index
2016	20
2015	30
2014	27
2013	25
2012	28
2011	100
2010	42
2009	32
2008	33
2007	38
2006	48
2005	45
2004	20
2003	55
2002	42
2001	42
2000	40
1999	45
1998	48
1997	59
1996	57
1995	43
1994	41
1993	48
1992	49
1991	57
1990	52

King William County compared with nearby places

Under 64
64 to 90
90 to 110
110 to 120
120 and over
No data

Highest daily Air Quality Index (US EPA), 2016, index. King William County is outlined. Same source and period for every area shown. Source: U.S. Environmental Protection Agency. Boundaries: U.S. Census Bureau cartographic boundary files.

Rankings

Counties in Virginia by highest daily Air Quality Index (US EPA) 60 places

Definition

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.

Report a problem with this figure

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 (Highest daily Air Quality Index (US EPA), King William County, 1990 to 2016) [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, Highest daily Air Quality Index (US EPA), King William County, 1990 to 2016. U.S. Environmental Protection Agency, 13 July 2026, https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Invokely, https://invokely.ai/en/highest-daily-air-quality-index/king-william-county-virginia. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Environmental Protection Agency. 2026. EPA AirData annual AQI by county: highest daily AQI. Highest daily Air Quality Index (US EPA), King William County, 1990 to 2016. Dataset. Accessed October 12, 2026. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Also distributed by Invokely, https://invokely.ai/en/highest-daily-air-quality-index/king-william-county-virginia.

Harvard

U.S. Environmental Protection Agency (2026) EPA AirData annual AQI by county: highest daily AQI, Highest daily Air Quality Index (US EPA), King William County, 1990 to 2016 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/en/highest-daily-air-quality-index/king-william-county-virginia (Accessed: 12 October 2026).

BibTeX

@misc{environmental_highest_daily_air_quality_2016,
  author = {{U.S. Environmental Protection Agency}},
  title = {{EPA AirData annual AQI by county: highest daily AQI: Highest daily Air Quality Index (US EPA), King William County, 1990 to 2016}},
  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/en/highest-daily-air-quality-index/king-william-county-virginia. 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: Highest daily Air Quality Index (US EPA), King William County, 1990 to 2016
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/en/highest-daily-air-quality-index/king-william-county-virginia
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/en/highest-daily-air-quality-index/king-william-county-virginia.
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  -

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.

Embed code

<iframe src="https://invokely.ai/embed/highest-daily-air-quality-index/king-william-county-virginia" width="760" height="440" title="Highest daily Air Quality Index (US EPA), King William County, chart from Invokely" loading="lazy" style="border:0;width:100%;max-width:760px" referrerpolicy="strict-origin-when-cross-origin"></iframe>

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:

What is the latest highest daily Air Quality Index (US EPA) in King William County? Cite the source.

get_value {"indicator":"aqi_max","place":"us-county-51101"}
GET https://invokely.ai/api/v1/value?indicator=aqi_max&place=us-county-51101

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

Questions

What is the highest daily Air Quality Index (US EPA) in King William County?

Highest daily Air Quality Index (US EPA) in King William County was 20 in 2016, according to the U.S. Environmental Protection Agency. That is down 10 from 2015.

Where does this figure come from?

U.S. Environmental Protection Agency. EPA AirData annual AQI by county: highest daily AQI. Retrieved by Invokely on 2026-10-12.

What was the highest highest daily Air Quality Index (US EPA) in King William County?

100 in 2011, the highest value since 1990 in this series.

Related statistics for King William County

All statistics for King William County | King William County in figures