Data / Highest daily Air Quality Index (US EPA) / Chatham County

Highest daily Air Quality Index (US EPA) in Chatham County

Highest daily Air Quality Index (US EPA) in Chatham County was 64 in 2015, according to the U.S. Environmental Protection Agency. That is down 23 from 2014.

2015, index64
Change on 2014-23
Series high1972002
Series low642015

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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Highest daily Air Quality Index (US EPA) in Chatham County, 1987 to 2015

5010015020019871995199920032007201120151987: 179 index1989: 143 index1992: 101 index1994: 122 index1995: 164 index1996: 177 index1997: 172 index1998: 174 index1999: 174 index2000: 147 index2001: 136 index2002: 197 index2003: 161 index2004: 112 index2005: 147 index2006: 126 index2007: 140 index2008: 162 index2009: 101 index2010: 108 index2011: 100 index2012: 151 index2013: 80 index2014: 87 index2015: 64 index501001502001987200020151987: 179 index1989: 143 index1992: 101 index1994: 122 index1995: 164 index1996: 177 index1997: 172 index1998: 174 index1999: 174 index2000: 147 index2001: 136 index2002: 197 index2003: 161 index2004: 112 index2005: 147 index2006: 126 index2007: 140 index2008: 162 index2009: 101 index2010: 108 index2011: 100 index2012: 151 index2013: 80 index2014: 87 index2015: 64 index
index. Source: EPA, EPA AirData annual AQI by county: highest daily AQI. Retrieved 2026-10-12, published 2026-07-13.
All 25 values
Periodindex
201564
201487
201380
2012151
2011100
2010108
2009101
2008162
2007140
2006126
2005147
2004112
2003161
2002197
2001136
2000147
1999174
1998174
1997172
1996177
1995164
1994122
1992101
1989143
1987179

Chatham County compared with nearby places

Alamance County: 67 indexAlexander County: 90 indexAvery County: 90 indexBuncombe County: 87 indexCaldwell County: 97 indexCarteret County: 71 indexCaswell County: 87 indexCatawba County: 84 indexChatham County: 64 indexCumberland County: 93 indexDavidson County: 85 indexDuplin County: 70 indexDurham County: 87 indexEdgecombe County: 77 indexForsyth County: 126 indexFranklin County: 93 indexGaston County: 65 indexGraham County: 97 indexGranville County: 87 indexGuilford County: 112 indexHaywood County: 101 indexHyde County: 66 indexJackson County: 100 indexJohnston County: 93 indexLee County: 94 indexLenoir County: 80 indexLincoln County: 112 indexMcDowell County: 89 indexMacon County: 80 indexMartin County: 71 indexMecklenburg County: 129 indexMitchell County: 63 indexMontgomery County: 80 indexNew Hanover County: 71 indexPerson County: 77 indexPitt County: 80 indexRockingham County: 112 indexRowan County: 122 indexSwain County: 87 indexUnion County: 101 indexWake County: 105 indexWatauga County: 85 indexWayne County: 87 indexYancey County: 97 index
  • Under 71
  • 71 to 81
  • 81 to 87
  • 87 to 93
  • 93 to 100
  • 100 and over
  • No data
Highest daily Air Quality Index (US EPA), 2015, index. Chatham 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

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.

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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), Chatham County, 1987 to 2015) [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), Chatham County, 1987 to 2015. 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/chatham-county-north-carolina. 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), Chatham County, 1987 to 2015. 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/chatham-county-north-carolina.

Harvard

U.S. Environmental Protection Agency (2026) EPA AirData annual AQI by county: highest daily AQI, Highest daily Air Quality Index (US EPA), Chatham County, 1987 to 2015 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/en/highest-daily-air-quality-index/chatham-county-north-carolina (Accessed: 12 October 2026).

BibTeX
@misc{environmental_highest_daily_air_quality_2015,
  author = {{U.S. Environmental Protection Agency}},
  title = {{EPA AirData annual AQI by county: highest daily AQI: Highest daily Air Quality Index (US EPA), Chatham County, 1987 to 2015}},
  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/chatham-county-north-carolina. 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), Chatham County, 1987 to 2015
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/chatham-county-north-carolina
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/en/highest-daily-air-quality-index/chatham-county-north-carolina.
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  -
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Questions

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

Highest daily Air Quality Index (US EPA) in Chatham County was 64 in 2015, according to the U.S. Environmental Protection Agency. That is down 23 from 2014.

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 Chatham County?

197 in 2002, the highest value since 1987 in this series.

Related statistics for Chatham County

All statistics for Chatham County | Chatham County in figures