Median Air Quality Index (US EPA) in Lassen County

Median Air Quality Index (US EPA) in Lassen County was 29 in 2001, according to the U.S. Environmental Protection Agency. That is up 1 from 2000.

2001, index29
Change on 2000+1
Series high321998
Series low181996

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 Lassen County, 1996 to 2001

15202530351996199719981999200020011996: 18 index1997: 22 index1998: 32 index1999: 28 index2000: 28 index2001: 29 index15202530351996199820011996: 18 index1997: 22 index1998: 32 index1999: 28 index2000: 28 index2001: 29 index
index. Source: EPA, EPA AirData annual AQI by county: median daily AQI. Retrieved 2026-10-12, published 2026-07-13.
All 6 values
Periodindex
200129
200028
199928
199832
199722
199618

Lassen County compared with nearby places

Alameda County: 41 indexAmador County: 40 indexButte County: 61 indexCalaveras County: 44 indexColusa County: 44 indexContra Costa County: 46 indexDel Norte County: 17 indexEl Dorado County: 60 indexFresno County: 119 indexGlenn County: 43 indexHumboldt County: 6 indexImperial County: 66 indexInyo County: 58 indexKern County: 108 indexKings County: 58 indexLake County: 37 indexLassen County: 29 indexLos Angeles County: 101 indexMadera County: 46 indexMarin County: 30 indexMariposa County: 49 indexMendocino County: 31 indexMerced County: 63 indexModoc County: 28 indexMono County: 39 indexMonterey County: 35 indexNapa County: 31 indexNevada County: 56 indexOrange County: 66 indexPlacer County: 46 indexPlumas County: 36 indexRiverside County: 110 indexSacramento County: 61 indexSan Benito County: 42 indexSan Bernardino County: 100 indexSan Diego County: 77 indexSan Francisco County: 38 indexSan Joaquin County: 45 indexSan Luis Obispo County: 44 indexSan Mateo County: 33 indexSanta Barbara County: 49 indexSanta Clara County: 51 indexSanta Cruz County: 36 indexShasta County: 44 indexSiskiyou County: 13 indexSolano County: 38 indexSonoma County: 37 indexStanislaus County: 51 indexSutter County: 44 indexTehama County: 44 indexTrinity County: 17 indexTulare County: 95 indexTuolumne County: 45 indexVentura County: 63 indexYolo County: 41 index
  • Under 33
  • 33 to 40
  • 40 to 44
  • 44 to 51
  • 51 to 63
  • 63 and over
  • No data
Median Air Quality Index (US EPA), 2001, index. Lassen 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), Lassen County, 1996 to 2001) [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), Lassen County, 1996 to 2001. 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/lassen-county-california. 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), Lassen County, 1996 to 2001. 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/lassen-county-california.

Harvard

U.S. Environmental Protection Agency (2026) EPA AirData annual AQI by county: median daily AQI, Median Air Quality Index (US EPA), Lassen County, 1996 to 2001 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/en/median-air-quality-index/lassen-county-california (Accessed: 12 October 2026).

BibTeX
@misc{environmental_median_air_quality_index_2001,
  author = {{U.S. Environmental Protection Agency}},
  title = {{EPA AirData annual AQI by county: median daily AQI: Median Air Quality Index (US EPA), Lassen County, 1996 to 2001}},
  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/lassen-county-california. 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), Lassen County, 1996 to 2001
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/lassen-county-california
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/en/median-air-quality-index/lassen-county-california.
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 Lassen County? Cite the source.
get_value {"indicator":"aqi_median","place":"us-county-06035"}
GET https://invokely.ai/api/v1/value?indicator=aqi_median&place=us-county-06035

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 Lassen County?

Median Air Quality Index (US EPA) in Lassen County was 29 in 2001, according to the U.S. Environmental Protection Agency. That is up 1 from 2000.

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 Lassen County?

32 in 1998, the highest value since 1996 in this series.

Related statistics for Lassen County

All statistics for Lassen County | Lassen County in figures