EnviroNearby

Grant County, Oklahoma air quality history

Daily Air Quality Index summaries from EPA monitors in Grant, Oklahoma, 2019–2025.

78%
Good days in 2023
32
Median daily AQI, 2023
0
Days above 100 in 2023
120
Days with an AQI in 2023 (of 365)

In 2023, EPA reported a daily Air Quality Index (AQI) for Grant, Oklahoma on 120 days. 94 of those days (78%) were in the Good range, and the median daily AQI was 32. That median is lower than the typical monitored county in Oklahoma (median 46 across 21 counties), and lower than the typical monitored U.S. county (43). The main pollutant was fine particles (PM2.5) on 120 days.

EPA did not report an AQI for every day of 2023 here (120 of 365 days). Figures describe monitored days only; seasonal monitoring (for example, ozone measured only in warmer months) can make a county look cleaner or dirtier than a full-year record would.

Years with fewer than 120 monitored days (2019, 2020, 2021, 2022, 2024, 2025) are shown in the table but left out of comparisons and trend statements.

How the days broke down each year

Each bar is one year. The colored segments show the share of monitored days that fell in each AQI category.

Share of monitored days in each AQI category, by year0%25%50%75%100%2019: Good 27 of 27 days20192020: Good 94 of 106 days2020: Moderate 12 of 106 days20202021: Good 90 of 107 days2021: Moderate 17 of 107 days20212022: Good 102 of 119 days2022: Moderate 17 of 119 days20222023: Good 94 of 120 days2023: Moderate 26 of 120 days20232024: Good 92 of 111 days2024: Moderate 19 of 111 days20242025: Good 84 of 102 days2025: Moderate 17 of 102 days2025: Unhealthy for Sensitive Groups 1 of 102 days2025
  • Good
  • Moderate
  • Unhealthy for Sensitive Groups
  • Unhealthy
  • Very Unhealthy
  • Hazardous

Typical and high-end AQI over time

The median is the middle day of the year. The 90th percentile is the level that only the highest 10% of days exceeded.

Median and 90th-percentile daily AQI, by year0501002019: 90th percentile AQI 422020: 90th percentile AQI 522021: 90th percentile AQI 522022: 90th percentile AQI 522023: 90th percentile AQI 562024: 90th percentile AQI 542025: 90th percentile AQI 532019: Median AQI 222020: Median AQI 262021: Median AQI 302022: Median AQI 282023: Median AQI 322024: Median AQI 322025: Median AQI 312019202020212022202320242025
  • Median daily AQI
  • 90th-percentile daily AQI

Main pollutant by day, 2023

On each monitored day, the AQI reflects whichever measured pollutant had the highest index. This counts how many days each pollutant set the AQI. A pollutant that was not measured here cannot appear.

PollutantDays as main pollutantShare of monitored days
Fine particles (PM2.5)120100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
2025102841710003153105PM2.5
202411192190000325486PM2.5
202312094260000325689PM2.5
2022119102170000285273PM2.5
202110790170000305266PM2.5
202010694120000265269PM2.5
2019272700000224243PM2.5

What this data can and can’t tell you

It is a county-level summary. EPA reports one AQI per day for the county, based on the monitors operating there. Air at a particular street, school or home can differ, especially near roads, industry or wildfire smoke.

It is not a health assessment. The AQI is EPA’s scale for communicating daily air quality. A county’s history can’t tell you what the health risk is for any particular person. For daily conditions and health guidance, see AirNow.

Rules change over time. EPA has revised AQI breakpoints, most recently for fine particles in 2024, so some year-to-year change can reflect the scale rather than the air.

Counties in Oklahoma with a similar median AQI in 2023

All monitored counties in Oklahoma

Source: U.S. EPA AirData, “Annual AQI by County” files for 2019–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem