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

Highest daily Air Quality Index (US EPA) in Elk County was 84 in 2025, according to the U.S. Environmental Protection Agency. That is up 17 from 2024. That is the 38th highest of 38 counties in 2025.

2025, index84
Change on 2024+17
Series high1972001
Series low672020

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 Elk County, 1990 to 2025

5010015020019901996200220082014202020251990: 174 index1991: 195 index1992: 177 index1993: 156 index1994: 140 index1995: 156 index1996: 164 index1997: 133 index1998: 185 index1999: 150 index2000: 169 index2001: 197 index2002: 179 index2003: 182 index2004: 122 index2005: 129 index2006: 150 index2007: 136 index2008: 119 index2009: 108 index2010: 115 index2011: 112 index2012: 156 index2013: 105 index2014: 115 index2015: 101 index2016: 126 index2017: 90 index2018: 97 index2019: 80 index2020: 67 index2021: 87 index2022: 101 index2023: 100 index2024: 67 index2025: 84 index5010015020019902002201420251990: 174 index1991: 195 index1992: 177 index1993: 156 index1994: 140 index1995: 156 index1996: 164 index1997: 133 index1998: 185 index1999: 150 index2000: 169 index2001: 197 index2002: 179 index2003: 182 index2004: 122 index2005: 129 index2006: 150 index2007: 136 index2008: 119 index2009: 108 index2010: 115 index2011: 112 index2012: 156 index2013: 105 index2014: 115 index2015: 101 index2016: 126 index2017: 90 index2018: 97 index2019: 80 index2020: 67 index2021: 87 index2022: 101 index2023: 100 index2024: 67 index2025: 84 index
index. Source: EPA, EPA AirData annual AQI by county: highest daily AQI. Retrieved 2026-10-12, published 2026-07-13.
All 36 values
Periodindex
202584
202467
2023100
2022101
202187
202067
201980
201897
201790
2016126
2015101
2014115
2013105
2012156
2011112
2010115
2009108
2008119
2007136
2006150
2005129
2004122
2003182
2002179
2001197
2000169
1999150
1998185
1997133
1996164
1995156
1994140
1993156
1992177
1991195
1990174

Elk County compared with nearby places

Adams County: 100 indexAllegheny County: 129 indexArmstrong County: 96 indexBeaver County: 131 indexBerks County: 122 indexBlair County: 115 indexBradford County: 109 indexBucks County: 136 indexCambria County: 115 indexCentre County: 101 indexChester County: 157 indexCumberland County: 96 indexDauphin County: 101 indexDelaware County: 153 indexElk County: 84 indexErie County: 149 indexFayette County: 93 indexFranklin County: 87 indexGreene County: 105 indexIndiana County: 122 indexLackawanna County: 117 indexLancaster County: 119 indexLebanon County: 108 indexLehigh County: 115 indexLycoming County: 105 indexMercer County: 115 indexMonroe County: 124 indexMontgomery County: 133 indexNorthampton County: 122 indexPhiladelphia County: 147 indexSomerset County: 93 indexSusquehanna County: 107 indexTioga County: 127 indexWarren County: 138 indexWashington County: 100 indexWestmoreland County: 126 indexWyoming County: 116 indexYork County: 116 index
  • Under 100
  • 100 to 110
  • 110 to 120
  • 120 to 130
  • 130 and over
  • No data
Highest daily Air Quality Index (US EPA), 2025, index. Elk 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), Elk County, 1990 to 2025) [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), Elk County, 1990 to 2025. 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/elk-county-pennsylvania. 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), Elk County, 1990 to 2025. 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/elk-county-pennsylvania.

Harvard

U.S. Environmental Protection Agency (2026) EPA AirData annual AQI by county: highest daily AQI, Highest daily Air Quality Index (US EPA), Elk County, 1990 to 2025 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/en/highest-daily-air-quality-index/elk-county-pennsylvania (Accessed: 12 October 2026).

BibTeX
@misc{environmental_highest_daily_air_quality_2025,
  author = {{U.S. Environmental Protection Agency}},
  title = {{EPA AirData annual AQI by county: highest daily AQI: Highest daily Air Quality Index (US EPA), Elk County, 1990 to 2025}},
  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/elk-county-pennsylvania. 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), Elk County, 1990 to 2025
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/elk-county-pennsylvania
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/en/highest-daily-air-quality-index/elk-county-pennsylvania.
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 Elk County?

Highest daily Air Quality Index (US EPA) in Elk County was 84 in 2025, according to the U.S. Environmental Protection Agency. That is up 17 from 2024. That is the 38th highest of 38 counties in 2025.

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 Elk County?

197 in 2001, the highest value since 1990 in this series.

Related statistics for Elk County

All statistics for Elk County | Elk County in figures