Data / Share of days with good air quality (US EPA AQI) / Union County

Share of days with good air quality (US EPA AQI) in Union County

Share of days with good air quality (US EPA AQI) in Union County was 53.6% in 2007, according to EPA. That is down 5.2 pts from 2006. That is the 14th highest of 25 counties in 2007.

200753.6%
Change on 2006-5.2 pts
Rank14th of 25Counties in South Carolina ranked
Series high83.71983
Series low53.62007

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

Get an email when a new figure is out or this one is revised.
Keep it in a collection in your library.

Share of days with good air quality (US EPA AQI) in Union County, 1983 to 2007

506070809019831987199119951999200320071983: 83.7 %1984: 70.7 %1985: 75.9 %1986: 62.8 %1987: 60.2 %1988: 75.7 %1989: 77.4 %1990: 68.3 %1991: 77.7 %1992: 82.2 %1993: 66.8 %1994: 76.7 %1995: 80 %1996: 80.8 %1997: 72.3 %1998: 69.7 %1999: 70.3 %2000: 68.8 %2001: 68.2 %2002: 58 %2003: 76 %2004: 68.4 %2005: 69.4 %2006: 58.8 %2007: 53.6 %50607080901983199220071983: 83.7 %1984: 70.7 %1985: 75.9 %1986: 62.8 %1987: 60.2 %1988: 75.7 %1989: 77.4 %1990: 68.3 %1991: 77.7 %1992: 82.2 %1993: 66.8 %1994: 76.7 %1995: 80 %1996: 80.8 %1997: 72.3 %1998: 69.7 %1999: 70.3 %2000: 68.8 %2001: 68.2 %2002: 58 %2003: 76 %2004: 68.4 %2005: 69.4 %2006: 58.8 %2007: 53.6 %
%. Source: Invokely calculation with data from EPA. Retrieved 2026-10-12, published 2026-07-13.
All 25 values
Period%
200753.6
200658.8
200569.4
200468.4
200376
200258
200168.2
200068.8
199970.3
199869.7
199772.3
199680.8
199580
199476.7
199366.8
199282.2
199177.7
199068.3
198977.4
198875.7
198760.2
198662.8
198575.9
198470.7
198383.7

Union County compared with nearby places

Abbeville County: 45.6 %Aiken County: 68 %Barnwell County: 75.1 %Beaufort County: 50.5 %Berkeley County: 91.4 %Charleston County: 35.3 %Cherokee County: 85.4 %Chester County: 56.6 %Chesterfield County: 58.6 %Colleton County: 77.7 %Darlington County: 65.7 %Edgefield County: 61.8 %Florence County: 34.5 %Georgetown County: 90.3 %Greenville County: 18.6 %Greenwood County: 31.3 %Horry County: 42.7 %Lexington County: 29.9 %Oconee County: 62.6 %Pickens County: 46.2 %Richland County: 25.5 %Spartanburg County: 30.1 %Union County: 53.6 %Williamsburg County: 72.2 %York County: 60.3 %
  • Under 34
  • 34 to 49
  • 49 to 61
  • 61 to 73
  • 73 and over
  • No data
Share of days with good air quality (US EPA AQI), 2007, %. Union 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

Definition

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.

Report a problem with this figure

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 (Share of days with good air quality (US EPA AQI), Union County, 1983 to 2007) [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, Share of days with good air quality (US EPA AQI), Union County, 1983 to 2007. U.S. Environmental Protection Agency, 13 July 2026, https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Invokely, https://invokely.ai/en/good-air-quality-days-share/union-county-south-carolina. 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. Share of days with good air quality (US EPA AQI), Union County, 1983 to 2007. Dataset. Accessed October 12, 2026. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Also distributed by Invokely, https://invokely.ai/en/good-air-quality-days-share/union-county-south-carolina.

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, Share of days with good air quality (US EPA AQI), Union County, 1983 to 2007 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/en/good-air-quality-days-share/union-county-south-carolina (Accessed: 12 October 2026).

BibTeX
@misc{environmental_share_of_days_with_2007,
  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: Share of days with good air quality (US EPA AQI), Union County, 1983 to 2007}},
  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/good-air-quality-days-share/union-county-south-carolina. 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: Share of days with good air quality (US EPA AQI), Union County, 1983 to 2007
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/good-air-quality-days-share/union-county-south-carolina
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/en/good-air-quality-days-share/union-county-south-carolina.
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:

What is the latest share of days with good air quality (US EPA AQI) in Union County? Cite the source.
get_value {"indicator":"aqi_good_days_share","place":"us-county-45087"}
GET https://invokely.ai/api/v1/value?indicator=aqi_good_days_share&place=us-county-45087

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

Questions

What is the share of days with good air quality (US EPA AQI) in Union County?

Share of days with good air quality (US EPA AQI) in Union County was 53.6% in 2007, according to EPA. That is down 5.2 pts from 2006. That is the 14th highest of 25 counties in 2007.

Where does this figure come from?

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 by Invokely on 2026-10-12.

What was the highest share of days with good air quality (US EPA AQI) in Union County?

83.7% in 1983, the highest value since 1983 in this series.

Related statistics for Union County

All statistics for Union County | Union County in figures