Data / Median Air Quality Index (US EPA) / Lemhi County

Median Air Quality Index (US EPA) in Lemhi County

Median Air Quality Index (US EPA) in Lemhi County was 29 in 2025, according to the U.S. Environmental Protection Agency. That is down 8 from 2024.

2025, index29
Change on 2024-8
Series high541990
Series low161994

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

Get an email when a new figure is out or this one is revised.
Keep it in a collection in your library.

Median Air Quality Index (US EPA) in Lemhi County, 1990 to 2025

10203040506019901996200220082014202020251990: 54 index1991: 38 index1992: 37 index1993: 25 index1994: 16 index1995: 16 index1996: 19 index1997: 20 index1998: 22 index1999: 20 index2000: 30 index2001: 29 index2002: 21 index2003: 24 index2004: 29 index2005: 38 index2006: 39 index2007: 35 index2008: 31 index2009: 33 index2010: 43 index2011: 46 index2012: 54 index2013: 51 index2014: 52 index2015: 51 index2016: 51 index2017: 37 index2018: 38 index2019: 31 index2020: 46 index2021: 47 index2022: 44 index2023: 32 index2024: 37 index2025: 29 index10203040506019902002201420251990: 54 index1991: 38 index1992: 37 index1993: 25 index1994: 16 index1995: 16 index1996: 19 index1997: 20 index1998: 22 index1999: 20 index2000: 30 index2001: 29 index2002: 21 index2003: 24 index2004: 29 index2005: 38 index2006: 39 index2007: 35 index2008: 31 index2009: 33 index2010: 43 index2011: 46 index2012: 54 index2013: 51 index2014: 52 index2015: 51 index2016: 51 index2017: 37 index2018: 38 index2019: 31 index2020: 46 index2021: 47 index2022: 44 index2023: 32 index2024: 37 index2025: 29 index
index. Source: EPA, EPA AirData annual AQI by county: median daily AQI. Retrieved 2026-10-12, published 2026-07-13.
All 36 values
Periodindex
202529
202437
202332
202244
202147
202046
201931
201838
201737
201651
201551
201452
201351
201254
201146
201043
200933
200831
200735
200639
200538
200429
200324
200221
200129
200030
199920
199822
199720
199619
199516
199416
199325
199237
199138
199054

Lemhi County compared with nearby places

Ada County: 42 indexBannock County: 36 indexBenewah County: 41 indexBlaine County: 17 indexBoise County: 42 indexBonner County: 47 indexBonneville County: 22 indexButte County: 42 indexCanyon County: 36 indexCuster County: 10 indexFranklin County: 21 indexIdaho County: 40 indexKootenai County: 31 indexLatah County: 31 indexLemhi County: 29 indexNez Perce County: 33 indexShoshone County: 44 indexTwin Falls County: 26 indexValley County: 34 index
  • Under 24
  • 24 to 31
  • 31 to 36
  • 36 to 42
  • 42 and over
  • No data
Median Air Quality Index (US EPA), 2025, index. Lemhi 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

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.

Report a problem with this figure

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 (Median Air Quality Index (US EPA), Lemhi 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: median daily AQI, Median Air Quality Index (US EPA), Lemhi 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/median-air-quality-index/lemhi-county-idaho. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Environmental Protection Agency. 2026. EPA AirData annual AQI by county: median daily AQI. Median Air Quality Index (US EPA), Lemhi 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/median-air-quality-index/lemhi-county-idaho.

Harvard

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

BibTeX
@misc{environmental_median_air_quality_index_2025,
  author = {{U.S. Environmental Protection Agency}},
  title = {{EPA AirData annual AQI by county: median daily AQI: Median Air Quality Index (US EPA), Lemhi 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/median-air-quality-index/lemhi-county-idaho. 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: Median Air Quality Index (US EPA), Lemhi 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/median-air-quality-index/lemhi-county-idaho
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/en/median-air-quality-index/lemhi-county-idaho.
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  -
Embed this chart

Paste this code into a web page or a blog post. The chart shows the latest figures as they are published, with the source and a link back to this page.

Sites that read oEmbed links, such as WordPress, can show the chart when you paste the link to this page.

Use this data in your AI agent

Invokely serves this figure to AI assistants through MCP and to code through a REST API, with the source and citation attached. Ask your assistant:

What is the latest median Air Quality Index (US EPA) in Lemhi County? Cite the source.
get_value {"indicator":"aqi_median","place":"us-county-16059"}
GET https://invokely.ai/api/v1/value?indicator=aqi_median&place=us-county-16059

Connect Claude, ChatGPT or Cursor in one step. The trial answers 25 calls a day without an account.

Questions

What is the median Air Quality Index (US EPA) in Lemhi County?

Median Air Quality Index (US EPA) in Lemhi County was 29 in 2025, according to the U.S. Environmental Protection Agency. That is down 8 from 2024.

Where does this figure come from?

U.S. Environmental Protection Agency. EPA AirData annual AQI by county: median daily AQI. Retrieved by Invokely on 2026-10-12.

What was the highest median Air Quality Index (US EPA) in Lemhi County?

54 in 1990, the highest value since 1990 in this series.

Related statistics for Lemhi County

All statistics for Lemhi County | Lemhi County in figures