Oklahoma · County air quality · 2025

Osage County, Oklahoma

Median AQI 42 (Good). 81.7% of monitored days rated Good, direct from EPA Air Quality System stations.

42
Median AQI
81.7%
Good-air days
0
Unhealthy days
61%
Cleaner than US counties

Osage County's 2025 annual median AQI is 42 (Good), with 81.7% Good days

According to the U.S. EPA Air Quality System, Osage County, Oklahoma posted a 2025 median AQI of 42 (Good) across 284 monitored days, with 81.7% rated Good and 0 unhealthy or worse. This is an annual comparison, not today's advisory.

Data source EPA Air Quality System (AQS)

Cleaner than US
Osage County's 81.7% Good-day share places it cleaner than 61% of US counties in 2025.
Closest median-AQI peer
Ada County (74.0% Good, median AQI 42) is the closest nationwide median-AQI peer to Osage County.
2020–2025 trend
Osage County's floor-qualifying Good-day share is worsening from 2020 to 2025 (92.0% → 81.7%).
Median AQI
Median AQI: 42

According to the 2025 EPA AQS county release on PlainAirData, Osage County, Oklahoma ranks #581 of 951 by median AQI (42) and #371 by good-day share (81.7%). Ponce County, Puerto Rico is #1 of 951 by median AQI (3, 91.4% Good days) at good-day-share #159 ≠ largest of 7 at 100.0% Good days #1 by good-day share (100.0%, median AQI 9) at median-AQI #7.

Annual release change

What changed in the 2025 EPA annual release

2024 → 2025
  • Osage County's Good-day share rose from 76.9% to 81.7% between the 2024 and 2025 EPA annual releases, a change of +4.8 percentage points.

Compared against 290 monitored days in 2024 and 284 in 2025. These are arithmetic differences between two stored EPA annual summaries, not a cause claim or a live advisory.

National release changes Two-year CSV

Data updated August 2026

Osage County AQI category distribution Stacked-segment bar showing the share of monitored days that fell in each EPA AQI category, Good, Moderate, USG, Unhealthy, Very Unhealthy, Hazardous, with median AQI marker. AQI category distribution 284 monitored days G M Median AQI 42 0 50 100 150 200 300 500 Osage County
  • Good · 232 d · 81.7%
  • Moderate · 50 d · 17.6%
  • USG · 2 d · 0.7%

How did Osage County's air break down in 2025?

Across 284 monitored days, 232 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 105 (USG).

EPA AQS →
Osage County, Good days share 81.7%
National avg

Share of monitored days at AQI 0-50 (Good band).

Osage County, Unhealthy-or-worse share 0.0%
National avg

Share of monitored days above AQI 150 (Unhealthy or worse). Bar maxes at 10% (worst-county ceiling).

Where Osage County sits nationally

COUNT-derived placement among 951 US counties with at least 100 monitored days in 2025. Osage County's Good-day share is 81.7% - cleaner than 61% of that comparison set.

Osage County Good-day share vs. every US county

Share of monitored days in the Good band (AQI 0–50) - EPA AQS annual release

81.7% Cleaner than 61% higher than 61% of 951 US counties

0.0%–5.0%: 0 US counties (0%). Below this entry. 5.0%–10.0%: 1 US counties (0%). Below this entry. 10.0%–15.0%: 4 US counties (0%). Below this entry. 15.0%–20.0%: 4 US counties (0%). Below this entry. 20.0%–25.0%: 1 US counties (0%). Below this entry. 25.0%–30.0%: 5 US counties (1%). Below this entry. 30.0%–35.0%: 9 US counties (1%). Below this entry. 35.0%–40.0%: 4 US counties (0%). Below this entry. 40.0%–45.0%: 16 US counties (2%). Below this entry. 45.0%–50.0%: 16 US counties (2%). Below this entry. 50.0%–55.0%: 32 US counties (3%). Below this entry. 55.0%–60.0%: 50 US counties (5%). Below this entry. 60.0%–65.0%: 77 US counties (8%). Below this entry. 65.0%–70.0%: 93 US counties (10%). Below this entry. 70.0%–75.0%: 109 US counties (11%). Below this entry. 75.0%–80.0%: 114 US counties (12%). Below this entry. 80.0%–85.0%: 123 US counties (13%). This entry sits in this band. 85.0%–90.0%: 99 US counties (10%). Above this entry. 90.0%–95.0%: 117 US counties (12%). Above this entry. 95.0%–100.0%: 70 US counties (7%). Above this entry. 100.0%–105.0%: 7 US counties (1%). Above this entry. This county 0.0% 100% every floor-qualified US county, bucketed by value

Each bar is a band; taller bars hold more US counties. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.

Source U.S. Environmental Protection Agency, Air Quality System (AQS) · 2025

Pollutant Breakdown

Days where each pollutant was the primary driver of AQI readings in Osage County.

Osage County, Oklahoma criteria pollutant distribution Stratified-band visualization showing the share of monitored days each criteria pollutant (PM2.5, PM10, O3, NO2, CO) was the primary AQI driver. Ozone · 100.0% 0% 25% 50% 75% 100% Osage County, Oklahoma · 284 monitored days Criteria pollutant column
  • Ozone · 284 days · 100.0%

2024 daily-monitor rhythm in Osage County

Month-by-month median AQI from EPA day-level county monitors (290 reported days in 2024). Aug posted the highest typical readings (median AQI 49, peak 112); Dec was cleanest at median 24. Summer months (Jun–Aug) averaged median AQI 46 vs 31 in Dec–Feb.

0 10 20 30 40 50 Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 37 40 47 47 44 44 49 44 48 31 24
Osage County median daily AQI by calendar month (2024, EPA daily county file)

Five-year seasonal record

EPA day-level county files · 2020–2024

1,555 daily readings show a recurring local pattern: Aug has the highest matched-month median AQI (49), while Dec is lowest (27). Each cell is that month’s median daily AQI, not a current-air forecast.

JanFebMarAprMayJunJulAugSepOctNovDec
2020 273238423946414337333228
2021 2933434335444544483933-
2022 -3743434045545846413226
2023 -3241464552464951323531
2024 -3740474744444944483124

Lower AQI is better. The colors summarize EPA AQI bands; gaps mean the county had no day-level record for that month.

Health Impact Assessment

Good

Osage County's air quality is rated Good based on 81.7% good air days. No unhealthy air days were recorded in 2025.

Air quality was acceptable on 81.7% of monitored days in 2025, with a median AQI of 42. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.

The dominant pollutant is Ozone, driving AQI on 284 of 284 monitored days.

5-Year Air Quality Trend

Air quality is worsening in Osage County. Highest Good-day share: 2020 (92.0%, 322 of 350 monitored days).

Year Good Moderate USG Unhealthy Median AQI
2020 322 28 0 0 36
2021 278 49 0 0 39
2022 221 64 5 2 44
2023 230 60 6 0 43
2024 223 62 5 0 44
2025 232 50 2 0 42

How does Osage County compare?

How Osage County compares

Good-day share better than typical
Osage County 81.7%
Ada County, Idaho 74.0%
Typical US county 76.0%
Median AQI worse than typical
Osage County 42
Ada County, Idaho 42
Typical US county 39
Unhealthy days / yr better than typical
Osage County 0
Ada County, Idaho 0
Typical US county 1

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by County dataset, 2020–2025 (aqs.epa.gov). For current conditions (not shown here — this page is historical annual data), see EPA AirNow (airnow.gov). See our methodology for how AQI, median, and coverage figures are computed.

Informational only, not professional advice. Data from EPA AQS. See our disclaimer. Spotted a figure that looks wrong? Report a correction.

Source: U.S. EPA Air Quality System (AQS) Annual AQI by county summary files for Osage County, Oklahoma · 2020–2025

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Download this county's annual AQI row as CSV , with the same EPA fields and denominator shown on this page.

Every figure on PlainAirData is rendered directly from EPA AQS air-quality monitoring data, no number is typed in by an editor. This page draws directly on EPA AQS air-quality monitoring data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.