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

Share of days with good air quality (US EPA AQI) in Orange County was 32.2% in 2008, according to EPA. That is down 5.6 pts from 2007.

200832.2%
Change on 2007-5.6 pts
Series high1001998
Series low282002

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

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Share of days with good air quality (US EPA AQI) in Orange County, 1994 to 2008

20406080100199419972000200320081994: 75.4 %1995: 93.4 %1996: 95.7 %1997: 95.1 %1998: 100 %1999: 66.5 %2000: 49.2 %2001: 28.6 %2002: 28 %2003: 33.3 %2004: 29.2 %2005: 34.2 %2006: 28.7 %2007: 37.8 %2008: 32.2 %2040608010019941999200420081994: 75.4 %1995: 93.4 %1996: 95.7 %1997: 95.1 %1998: 100 %1999: 66.5 %2000: 49.2 %2001: 28.6 %2002: 28 %2003: 33.3 %2004: 29.2 %2005: 34.2 %2006: 28.7 %2007: 37.8 %2008: 32.2 %
%. Source: Invokely calculation with data from EPA. Retrieved 2026-10-12, published 2026-07-13.
All 15 values
Period%
200832.2
200737.8
200628.7
200534.2
200429.2
200333.3
200228
200128.6
200049.2
199966.5
1998100
199795.1
199695.7
199593.4
199475.4

Orange County compared with nearby places

Alamance County: 29.2 %Alexander County: 62.6 %Avery County: 69.1 %Buncombe County: 43.1 %Caldwell County: 65.9 %Carteret County: 94.9 %Caswell County: 34.2 %Catawba County: 24.7 %Chatham County: 63.5 %Cumberland County: 30.9 %Davidson County: 30.2 %Davie County: 57.5 %Duplin County: 46.8 %Durham County: 31.2 %Edgecombe County: 55.3 %Forsyth County: 21.6 %Franklin County: 65 %Gaston County: 26.6 %Graham County: 62.3 %Granville County: 55.6 %Guilford County: 27.4 %Haywood County: 38.4 %Henderson County: 100 %Hyde County: 63.7 %Jackson County: 41.3 %Johnston County: 62.1 %Lenoir County: 57.4 %Lincoln County: 58.9 %McDowell County: 27.6 %Macon County: 97.4 %Martin County: 44.7 %Mecklenburg County: 22.1 %Mitchell County: 47.9 %Montgomery County: 66.2 %New Hanover County: 80.9 %Orange County: 32.2 %Person County: 64.8 %Pitt County: 51.9 %Robeson County: 39.7 %Rockingham County: 56.5 %Rowan County: 25.1 %Swain County: 33.2 %Union County: 62.4 %Wake County: 29.2 %Watauga County: 54.5 %Wayne County: 37.2 %Yancey County: 52.4 %
  • Under 29
  • 29 to 38
  • 38 to 52
  • 52 to 58
  • 58 to 65
  • 65 and over
  • No data
Share of days with good air quality (US EPA AQI), 2008, %. Orange 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.

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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), Orange County, 1994 to 2008) [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), Orange County, 1994 to 2008. 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/orange-county-north-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), Orange County, 1994 to 2008. 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/orange-county-north-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), Orange County, 1994 to 2008 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/en/good-air-quality-days-share/orange-county-north-carolina (Accessed: 12 October 2026).

BibTeX
@misc{environmental_share_of_days_with_2008,
  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), Orange County, 1994 to 2008}},
  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/orange-county-north-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), Orange County, 1994 to 2008
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/orange-county-north-carolina
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/en/good-air-quality-days-share/orange-county-north-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  - 
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Questions

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

Share of days with good air quality (US EPA AQI) in Orange County was 32.2% in 2008, according to EPA. That is down 5.6 pts from 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 Orange County?

100% in 1998, the highest value since 1994 in this series.

Related statistics for Orange County

All statistics for Orange County | Orange County in figures