Counties in North Carolina by median Air Quality Index (US EPA)

Rowan County had the highest median Air Quality Index (US EPA) of 51 counties in 2002, at 64. Henderson County had the lowest, at 20. The median was 54. Source: the U.S. Environmental Protection Agency.

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Highest64Rowan County
Median5451 counties

Map of counties, 2002

Alamance County: 57 indexAlexander County: 54 indexAvery County: 46 indexBuncombe County: 52 indexCabarrus County: 58 indexCaldwell County: 49 indexCarteret County: 38 indexCaswell County: 56 indexCatawba County: 62 indexChatham County: 54 indexCumberland County: 47 indexDavidson County: 60 indexDavie County: 58 indexDuplin County: 52 indexDurham County: 58 indexEdgecombe County: 56 indexForsyth County: 61 indexFranklin County: 51 indexGaston County: 57 indexGranville County: 51 indexGuilford County: 58 indexHaywood County: 61 indexHenderson County: 20 indexHyde County: 39 indexJackson County: 58 indexJohnston County: 54 indexLenoir County: 52 indexLincoln County: 50 indexMcDowell County: 58 indexMacon County: 36 indexMartin County: 47 indexMecklenburg County: 62 indexMitchell County: 57 indexMontgomery County: 44 indexNew Hanover County: 39 indexNorthampton County: 47 indexOnslow County: 52 indexOrange County: 56 indexPasquotank County: 53 indexPerson County: 51 indexPitt County: 53 indexRandolph County: 49 indexRobeson County: 56 indexRockingham County: 51 indexRowan County: 64 indexSwain County: 48 indexUnion County: 54 indexWake County: 60 indexWatauga County: 52 indexWayne County: 57 indexYancey County: 58 index
  • Under 47
  • 47 to 51
  • 51 to 54
  • 54 to 57
  • 57 to 58
  • 58 and over
  • No data
index, 2002. Hatched areas have no value for this period. Source: EPA, EPA AirData annual AQI by county: median daily AQI. Boundaries: U.S. Census Bureau cartographic boundary files.

All counties, 2002

Rowan County: 64 indexRowan County64Catawba County: 62 indexCatawba County62Mecklenburg County: 62 indexMecklenburg County62Forsyth County: 61 indexForsyth County61Haywood County: 61 indexHaywood County61Davidson County: 60 indexDavidson County60Wake County: 60 indexWake County60Cabarrus County: 58 indexCabarrus County58Davie County: 58 indexDavie County58Durham County: 58 indexDurham County58Guilford County: 58 indexGuilford County58Jackson County: 58 indexJackson County58McDowell County: 58 indexMcDowell County58Yancey County: 58 indexYancey County58Alamance County: 57 indexAlamance County57Gaston County: 57 indexGaston County57Mitchell County: 57 indexMitchell County57Wayne County: 57 indexWayne County57Caswell County: 56 indexCaswell County56Edgecombe County: 56 indexEdgecombe County56Orange County: 56 indexOrange County56Robeson County: 56 indexRobeson County56Alexander County: 54 indexAlexander County54Chatham County: 54 indexChatham County54Johnston County: 54 indexJohnston County54Union County: 54 indexUnion County54Pasquotank County: 53 indexPasquotank County53Pitt County: 53 indexPitt County53Buncombe County: 52 indexBuncombe County52Duplin County: 52 indexDuplin County52Lenoir County: 52 indexLenoir County52Onslow County: 52 indexOnslow County52Watauga County: 52 indexWatauga County52Franklin County: 51 indexFranklin County51Granville County: 51 indexGranville County51Person County: 51 indexPerson County51Rockingham County: 51 indexRockingham County51Lincoln County: 50 indexLincoln County50Caldwell County: 49 indexCaldwell County49Randolph County: 49 indexRandolph County49Swain County: 48 indexSwain County48Cumberland County: 47 indexCumberland County47Martin County: 47 indexMartin County47Northampton County: 47 indexNorthampton County47Avery County: 46 indexAvery County46Montgomery County: 44 indexMontgomery County44Hyde County: 39 indexHyde County39New Hanover County: 39 indexNew Hanover County39Carteret County: 38 indexCarteret County38Macon County: 36 indexMacon County36Henderson County: 20 indexHenderson County20Rowan County: 64 indexRowan County64Catawba County: 62 indexCatawba County62Mecklenburg County: 62 indexMecklenburg County62Forsyth County: 61 indexForsyth County61Haywood County: 61 indexHaywood County61Davidson County: 60 indexDavidson County60Wake County: 60 indexWake County60Cabarrus County: 58 indexCabarrus County58Davie County: 58 indexDavie County58Durham County: 58 indexDurham County58Guilford County: 58 indexGuilford County58Jackson County: 58 indexJackson County58McDowell County: 58 indexMcDowell County58Yancey County: 58 indexYancey County58Alamance County: 57 indexAlamance County57Gaston County: 57 indexGaston County57Mitchell County: 57 indexMitchell County57Wayne County: 57 indexWayne County57Caswell County: 56 indexCaswell County56Edgecombe County: 56 indexEdgecombe County56Orange County: 56 indexOrange County56Robeson County: 56 indexRobeson County56Alexander County: 54 indexAlexander County54Chatham County: 54 indexChatham County54Johnston County: 54 indexJohnston County54Union County: 54 indexUnion County54Pasquotank County: 53 indexPasquotank County53Pitt County: 53 indexPitt County53Buncombe County: 52 indexBuncombe County52Duplin County: 52 indexDuplin County52Lenoir County: 52 indexLenoir County52Onslow County: 52 indexOnslow County52Watauga County: 52 indexWatauga County52Franklin County: 51 indexFranklin County51Granville County: 51 indexGranville County51Person County: 51 indexPerson County51Rockingham County: 51 indexRockingham County51Lincoln County: 50 indexLincoln County50Caldwell County: 49 indexCaldwell County49Randolph County: 49 indexRandolph County49Swain County: 48 indexSwain County48Cumberland County: 47 indexCumberland County47Martin County: 47 indexMartin County47Northampton County: 47 indexNorthampton County47Avery County: 46 indexAvery County46Montgomery County: 44 indexMontgomery County44Hyde County: 39 indexHyde County39New Hanover County: 39 indexNew Hanover County39Carteret County: 38 indexCarteret County38Macon County: 36 indexMacon County36Henderson County: 20 indexHenderson County20
index. Source: EPA, EPA AirData annual AQI by county: median daily AQI. Retrieved 2026-10-12.

Full ranking

Other periods

About this ranking

Median of the daily Air Quality Index (AQI) values of a US county over the days of the year with an AQI, from the EPA AirData annual summaries.

More on how it is measured
  • The daily county AQI is the highest AQI among the monitors and pollutants reported that day (ozone, PM2.5, PM10, carbon monoxide and nitrogen dioxide).
  • Lower is cleaner: 0 to 50 is good, 51 to 100 moderate and above 100 unhealthy for sensitive groups.

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. 11 counties with data in other periods have no value for 2002 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: median 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: median daily AQI (Counties in North Carolina by median Air Quality Index (US EPA), 2002) [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: median daily AQI, Counties in North Carolina by median Air Quality Index (US EPA), 2002. U.S. Environmental Protection Agency, 13 July 2026, https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Invokely, https://invokely.ai/rankings/median-air-quality-index/north-carolina-counties?period=2002. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Environmental Protection Agency. 2026. EPA AirData annual AQI by county: median daily AQI. Counties in North Carolina by median Air Quality Index (US EPA), 2002. Dataset. Accessed October 12, 2026. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Also distributed by Invokely, https://invokely.ai/rankings/median-air-quality-index/north-carolina-counties?period=2002.

Harvard

U.S. Environmental Protection Agency (2026) EPA AirData annual AQI by county: median daily AQI, Counties in North Carolina by median Air Quality Index (US EPA), 2002 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/rankings/median-air-quality-index/north-carolina-counties?period=2002 (Accessed: 12 October 2026).

BibTeX
@misc{environmental_counties_in_north_carolina_2002,
  author = {{U.S. Environmental Protection Agency}},
  title = {{EPA AirData annual AQI by county: median daily AQI: Counties in North Carolina by median Air Quality Index (US EPA), 2002}},
  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/median-air-quality-index/north-carolina-counties?period=2002. Publisher attribution: U.S. Environmental Protection Agency, Air Quality System, AirData. EPA AirData annual AQI by county: median 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: median daily AQI: Counties in North Carolina by median Air Quality Index (US EPA), 2002
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/median-air-quality-index/north-carolina-counties?period=2002
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/median-air-quality-index/north-carolina-counties?period=2002.
N1  - Publisher attribution: U.S. Environmental Protection Agency, Air Quality System, AirData. EPA AirData annual AQI by county: median daily AQI. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Retrieved 2026-10-12.
ER  - 
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Rank Counties in North Carolina by median Air Quality Index (US EPA) using official data, and cite the source.
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Questions

Which county has the highest median Air Quality Index (US EPA)?

Rowan County, with 64 in 2002, according to the U.S. Environmental Protection Agency.

Which county has the lowest median Air Quality Index (US EPA)?

Henderson County, with 20 in 2002.

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: median daily AQI. Retrieved 2026-10-12. 11 counties have no value for 2002 and are not ranked.

Median Air Quality Index (US EPA): other rankings

Counties in North Carolina: more rankings