Data / Share of days with good air quality (US EPA AQI) / Marion County

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

Share of days with good air quality (US EPA AQI) in Marion County was 69.7% in 2001, according to EPA. That is up 11.1 pts from 2000.

200169.7%
Change on 2000+11.1 pts
Series high77.61998
Series low58.62000

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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Share of days with good air quality (US EPA AQI) in Marion County, 1998 to 2001

55606570758019981999200020011998: 77.6 %1999: 58.7 %2000: 58.6 %2001: 69.7 %556065707580199820011998: 77.6 %1999: 58.7 %2000: 58.6 %2001: 69.7 %
%. Source: Invokely calculation with data from EPA. Retrieved 2026-10-12, published 2026-07-13.
All 4 values
Period%
200169.7
200058.6
199958.7
199877.6

Marion County compared with nearby places

Bexar County: 47.4 %Bowie County: 25.4 %Brazoria County: 68.3 %Brewster County: 90.8 %Caldwell County: 61.6 %Cameron County: 75.9 %Collin County: 56.4 %Culberson County: 89.1 %Dallas County: 18.4 %Denton County: 72.3 %Ector County: 72 %Ellis County: 84.1 %El Paso County: 24.7 %Galveston County: 62.7 %Gregg County: 61.4 %Harris County: 18.9 %Harrison County: 56.4 %Hidalgo County: 67.7 %Hood County: 79.9 %Jefferson County: 37 %Johnson County: 76.4 %Kaufman County: 78.9 %Lubbock County: 75.8 %McLennan County: 52.8 %Marion County: 69.7 %Montgomery County: 66.1 %Nueces County: 64.4 %Orange County: 66.6 %Parker County: 78.6 %Potter County: 79.4 %Rockwall County: 74.8 %Smith County: 72.7 %Tarrant County: 24.4 %Travis County: 38.6 %Victoria County: 86.6 %Webb County: 77.8 %
  • Under 38
  • 38 to 62
  • 62 to 68
  • 68 to 75
  • 75 to 79
  • 79 and over
  • No data
Share of days with good air quality (US EPA AQI), 2001, %. Marion 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

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), Marion County, 1998 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: good days as a share of days with an AQI, calculated with stored counts, Share of days with good air quality (US EPA AQI), Marion County, 1998 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/good-air-quality-days-share/marion-county-texas. 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), Marion County, 1998 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/good-air-quality-days-share/marion-county-texas.

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), Marion County, 1998 to 2001 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/en/good-air-quality-days-share/marion-county-texas (Accessed: 12 October 2026).

BibTeX
@misc{environmental_share_of_days_with_2001,
  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), Marion County, 1998 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/good-air-quality-days-share/marion-county-texas. 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), Marion County, 1998 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/good-air-quality-days-share/marion-county-texas
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/en/good-air-quality-days-share/marion-county-texas.
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 Marion County?

Share of days with good air quality (US EPA AQI) in Marion County was 69.7% in 2001, according to EPA. That is up 11.1 pts from 2000.

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 Marion County?

77.6% in 1998, the highest value since 1998 in this series.

Related statistics for Marion County

All statistics for Marion County | Marion County in figures