Share of days with good air quality (US EPA AQI) in Pinal County

Share of days with good air quality (US EPA AQI) in Pinal County was 17% in 2025, according to EPA. That is down 4 pts from 2024. That is the 12th highest of 13 counties in 2025.

202517%

Change on 2024-4 pts

Rank12th of 13Counties in Arizona ranked

Series high67.52000

Series low5.52006

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

Share of days with good air quality (US EPA AQI) in Pinal County, 1999 to 2025

%. Source: Invokely calculation with data from EPA. Retrieved 2026-10-12, published 2026-07-13.

All 27 values

Period	%
2025	17
2024	21
2023	29.9
2022	24.9
2021	19.7
2020	23.5
2019	28.5
2018	19.5
2017	15.1
2016	15.6
2015	23.6
2014	14
2013	24.9
2012	12.6
2011	17.8
2010	24.1
2009	11.2
2008	15.6
2007	10.7
2006	5.5
2005	49
2004	57.4
2003	44.7
2002	48.2
2001	45.7
2000	67.5
1999	64.7

Pinal County compared with nearby places

Under 41
41 to 61
61 to 70
70 to 82
82 and over
No data

Share of days with good air quality (US EPA AQI), 2025, %. Pinal 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

Counties in Arizona by share of days with good air quality (US EPA AQI) 15 places

Definition

Days with a daily Air Quality Index of 0 to 50 (good) as a percentage of the days of the year with an AQI in a US county. Calculated by Invokely from the day counts in the EPA AirData annual summaries; both counts are stored with each value.

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: good days as a share of days with an AQI, calculated with stored counts. 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: good days as a share of days with an AQI, calculated with stored counts (Share of days with good air quality (US EPA AQI), Pinal County, 1999 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: good days as a share of days with an AQI, calculated with stored counts, Share of days with good air quality (US EPA AQI), Pinal County, 1999 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/good-air-quality-days-share/pinal-county-arizona. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Environmental Protection Agency. 2026. EPA AirData annual AQI by county: good days as a share of days with an AQI, calculated with stored counts. Share of days with good air quality (US EPA AQI), Pinal County, 1999 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/good-air-quality-days-share/pinal-county-arizona.

Harvard

U.S. Environmental Protection Agency (2026) EPA AirData annual AQI by county: good days as a share of days with an AQI, calculated with stored counts, Share of days with good air quality (US EPA AQI), Pinal County, 1999 to 2025 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/en/good-air-quality-days-share/pinal-county-arizona (Accessed: 12 October 2026).

BibTeX

@misc{environmental_share_of_days_with_2025,
  author = {{U.S. Environmental Protection Agency}},
  title = {{EPA AirData annual AQI by county: good days as a share of days with an AQI, calculated with stored counts: Share of days with good air quality (US EPA AQI), Pinal County, 1999 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/good-air-quality-days-share/pinal-county-arizona. Publisher attribution: U.S. Environmental Protection Agency, Air Quality System, AirData. EPA AirData annual AQI by county: good days as a share of days with an AQI, calculated with stored counts. 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: good days as a share of days with an AQI, calculated with stored counts: Share of days with good air quality (US EPA AQI), Pinal County, 1999 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/good-air-quality-days-share/pinal-county-arizona
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/en/good-air-quality-days-share/pinal-county-arizona.
N1  - Publisher attribution: U.S. Environmental Protection Agency, Air Quality System, AirData. EPA AirData annual AQI by county: good days as a share of days with an AQI, calculated with stored counts. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Retrieved 2026-10-12.
ER  -

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Questions

What is the share of days with good air quality (US EPA AQI) in Pinal County?

Share of days with good air quality (US EPA AQI) in Pinal County was 17% in 2025, according to EPA. That is down 4 pts from 2024. That is the 12th highest of 13 counties in 2025.

Where does this figure come from?

U.S. Environmental Protection Agency. EPA AirData annual AQI by county: good days as a share of days with an AQI, calculated with stored counts. Retrieved by Invokely on 2026-10-12.

What was the highest share of days with good air quality (US EPA AQI) in Pinal County?

67.5% in 2000, the highest value since 1999 in this series.

Related statistics for Pinal County

All statistics for Pinal County | Pinal County in figures