Counties in Nevada by highest daily Air Quality Index (US EPA)

Washoe County had the highest highest daily Air Quality Index (US EPA) of 9 counties in 2014, at 935. Churchill County had the lowest, at 100. The median was 135. Source: the U.S. Environmental Protection Agency.

Keep it in a collection in your library.
Highest935Washoe County
Median1359 counties

Map of counties, 2014

Churchill County: 100 indexClark County: 160 indexDouglas County: 135 indexElko County: 123 indexLyon County: 112 indexNye County: 143 indexWashoe County: 935 indexWhite Pine County: 101 indexCarson City: 166 index
  • Under 110
  • 110 to 130
  • 130 to 140
  • 140 to 160
  • 160 and over
  • No data
index, 2014. Hatched areas have no value for this period. Source: EPA, EPA AirData annual AQI by county: highest daily AQI. Boundaries: U.S. Census Bureau cartographic boundary files.

All counties, 2014

Washoe County: 935 indexWashoe County935Carson City: 166 indexCarson City166Clark County: 160 indexClark County160Nye County: 143 indexNye County143Douglas County: 135 indexDouglas County135Elko County: 123 indexElko County123Lyon County: 112 indexLyon County112White Pine County: 101 indexWhite Pine County101Churchill County: 100 indexChurchill County100Washoe County: 935 indexWashoe County935Carson City: 166 indexCarson City166Clark County: 160 indexClark County160Nye County: 143 indexNye County143Douglas County: 135 indexDouglas County135Elko County: 123 indexElko County123Lyon County: 112 indexLyon County112White Pine County: 101 indexWhite Pine County101Churchill County: 100 indexChurchill County100
index. Source: EPA, EPA AirData annual AQI by county: highest daily AQI. Retrieved 2026-10-12.

Full ranking

RankCounties2014
index
Change on 2013
1Washoe County935-4
2Carson City166-79
3Clark County160-6
4Nye County143+10
5Douglas County135-175
6Elko County123+40
7Lyon County112+22
8White Pine County101-18
9Churchill County100+13

Other periods

About this ranking

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.

Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. 3 counties with data in other periods have no value for 2014 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: 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 (Counties in Nevada by highest daily Air Quality Index (US EPA), 2014) [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, Counties in Nevada by highest daily Air Quality Index (US EPA), 2014. U.S. Environmental Protection Agency, 13 July 2026, https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Invokely, https://invokely.ai/rankings/highest-daily-air-quality-index/nevada-counties?period=2014. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Environmental Protection Agency. 2026. EPA AirData annual AQI by county: highest daily AQI. Counties in Nevada by highest daily Air Quality Index (US EPA), 2014. Dataset. Accessed October 12, 2026. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Also distributed by Invokely, https://invokely.ai/rankings/highest-daily-air-quality-index/nevada-counties?period=2014.

Harvard

U.S. Environmental Protection Agency (2026) EPA AirData annual AQI by county: highest daily AQI, Counties in Nevada by highest daily Air Quality Index (US EPA), 2014 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/rankings/highest-daily-air-quality-index/nevada-counties?period=2014 (Accessed: 12 October 2026).

BibTeX
@misc{environmental_counties_in_nevada_by_2014,
  author = {{U.S. Environmental Protection Agency}},
  title = {{EPA AirData annual AQI by county: highest daily AQI: Counties in Nevada by highest daily Air Quality Index (US EPA), 2014}},
  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/highest-daily-air-quality-index/nevada-counties?period=2014. 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: Counties in Nevada by highest daily Air Quality Index (US EPA), 2014
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/highest-daily-air-quality-index/nevada-counties?period=2014
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/highest-daily-air-quality-index/nevada-counties?period=2014.
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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Rank Counties in Nevada by highest daily Air Quality Index (US EPA) using official data, and cite the source.
rank_places {"indicator":"aqi_max","level":"province","within":"Nevada","limit":10}
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Questions

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

Washoe County, with 935 in 2014, according to the U.S. Environmental Protection Agency.

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

Churchill County, with 100 in 2014.

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: highest daily AQI. Retrieved 2026-10-12. 3 counties have no value for 2014 and are not ranked.

Highest daily Air Quality Index (US EPA): other rankings

Counties in Nevada: more rankings