Median AQI
51
Moderate
Oklahoma · County air quality · 2025
Oklahoma County, Oklahoma
Median AQI 51 (Moderate). 48.2% of monitored days rated Good, direct from EPA Air Quality System stations.
- 51
- Median AQI
- 48.2%
- Good-air days
- 1
- Unhealthy days
- 6%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Oklahoma County's air is moderate on balance, among the most polluted counties nationally, a median AQI of 51 with 48.2% of 274 monitored days in the Good band, driven mainly by PM2.5.
- 51
- median AQI · Moderate
- 48.2%
- days rated Good
- PM2.5
- main pollutant
- 6%
- cleaner than US counties
1 day reached Unhealthy or worse; the worst single reading hit AQI 459.
Data updated July 2026
- Good · 132 d · 48.2%
- Moderate · 135 d · 49.3%
- USG · 6 d · 2.2%
- Hazardous · 1 d · 0.4%
How did Oklahoma County's air break down in 2025?
Across 274 monitored days, 132 fell in the Good band (AQI 0–50) and 1 reached Unhealthy or worse. The worst single day peaked at AQI 459 (Hazardous).
EPA AQS →Air quality data from EPA Air Quality System (2025). 274 days monitored. Median AQI: 51 (Moderate).
Insights: Oklahoma County, Oklahoma. EPA monitors recorded a median Air Quality Index of 51 across 274 measured days in 2025, earning a Moderate classification and a Poor health grade. Of those days, 132 (48%) fell in the Good band (AQI 0–50), 135 (49%) registered Moderate readings, and 6 (2%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 74, while the worst single-day peak hit 459 (Hazardous). Residents averaged about 14.5 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (138 days), Ozone (127 days), NO2 (5 days), PM10 (3 days), CO (1 days). Across the 2020–2025 trend window, good days shifted by -15 and the median AQI moved -2 points, placing the multi-year trajectory at improving. Residents and visitors experienced 1 unhealthy-or-worse days combined, periods when the EPA recommends sensitive groups limit prolonged outdoor exertion. Nearby counties show comparable readings: Adair (59.2% good, AQI 45); Canadian (78.0% good, AQI 44); Carter (80.9% good, AQI 33); Cleveland (53.7% good, AQI 49); Comanche (63.8% good, AQI 45); Creek (80.1% good, AQI 43).
Air Quality Summary
Good Days
48.2%
132 of 274 monitored days
-26.8pp vs 75% target
Max AQI Recorded
459
Hazardous
Health Grade
Poor
90th-pct AQI 74
Oklahoma County, Good days share 48.2%
National avg
Share of monitored days at AQI 0-50 (Good band).
Oklahoma County, Unhealthy-or-worse share 0.4%
National avg
Share of monitored days above AQI 150 (Unhealthy or worse). Bar maxes at 10% (worst-county ceiling).
AQI Day Breakdown (2025)
Distribution of 274 monitored days across EPA AQI categories.
Good
132
48%
Moderate
135
49%
USG
6
2%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
1
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Oklahoma County.
- PM2.5 · 138 days · 50.4%
- Ozone · 127 days · 46.4%
- NO₂ · 5 days · 1.8%
- PM10 · 3 days · 1.1%
- CO · 1 days · 0.4%
Health Impact Assessment
Poor
Oklahoma County's air quality is rated Poor based on 48.2% good air days. There were 1 unhealthy days in 2025 when outdoor activity should be limited.
Air quality posed significant health risk in 2025. Sensitive groups, including people with asthma, COPD, cardiovascular conditions, children, pregnant women, and adults over 65, should monitor AirNow.gov alerts and limit outdoor activity on Unhealthy (AQI 151+) and Very Unhealthy (201+) days. Peak readings reached AQI 459, well into the Hazardous range.
Sensitive group advisory
People with asthma, COPD, heart disease, children, pregnant women, and adults 65+ should follow EPA AQI alerts daily and limit outdoor exertion when AQI exceeds 100. Real-time conditions: airnow.gov.
The dominant pollutant is PM2.5, driving AQI on 138 of 274 monitored days.
5-Year Air Quality Trend
Air quality is improving in Oklahoma County. Best year: 2024 (172 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 147 | 215 | 4 | 0 | 53 | 112 |
| 2021 | 125 | 234 | 6 | 0 | 54 | 140 |
| 2022 | 144 | 215 | 6 | 0 | 54 | 129 |
| 2023 | 150 | 210 | 5 | 0 | 53 | 136 |
| 2024 | 172 | 183 | 11 | 0 | 52 | 147 |
| 2025 | 132 | 135 | 6 | 0 | 51 | 459 |
How does Oklahoma County compare?
How Oklahoma County compares
Good-day share worse than US avg
Oklahoma County 48.2%
Adair County, Oklahoma 59.2%
US average 76.5%
Median AQI worse than US avg
Oklahoma County 51
Adair County, Oklahoma 45
US average 38
Unhealthy days / yr worse than US avg
Oklahoma County 1
Adair County, Oklahoma 2
US average 0
Other Counties in Oklahoma
Air quality comparison for nearby counties in Oklahoma.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Oklahoma County.
Arapahoe County, Colorado
AQI 51 · 47.3% good
Bibb County, Georgia
AQI 51 · 49.5% good
East Baton Rouge County, Louisiana
AQI 51 · 49.3% good
Eddy County, New Mexico
AQI 51 · 46.9% good
Hillsborough County, Florida
AQI 51 · 49.3% good
Jefferson County, Colorado
AQI 51 · 46.5% good
What Oklahoma County's air means for you
On most days the air here is fine, but PM2.5 drives 1 unhealthy-or-worse day a year that sensitive groups should plan around.
- Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-PM2.5 days, the guide explains what a median of 51 means for exposure. Health guidance
- See how Oklahoma County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Oklahoma County with its Oklahoma neighbours before drawing a conclusion about the region. All of Oklahoma
Based on 274 EPA-monitored days in 2025; figures reflect only days the monitors reported. Source: EPA Air Quality System annual summaries.
More Air Quality Data
Air Quality Guides
Frequently Asked Questions
What is the air quality in Oklahoma County, Oklahoma? ▼
Oklahoma County has a median Air Quality Index (AQI) of 51, rated "Moderate." 48.2% of monitored days (132 out of 274) had good air quality in 2025.
What is the main pollutant in Oklahoma County? ▼
The primary pollutant in Oklahoma County is Fine Particles (PM2.5), which was the main AQI driver on 138 days (50% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Oklahoma County have? ▼
In 2025, Oklahoma County recorded 1 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 1 Hazardous). The maximum AQI reached 459.
Is the air quality in Oklahoma County getting better or worse? ▼
Air quality in Oklahoma County is improving based on 5-year trends (2020-2025). Best year: 2024 with 172 good days. Worst year: 2021 with 125 good days.
What does AQI 51 mean for health? ▼
Oklahoma County's median AQI of 51 falls in the "Moderate" category. See the <a href="/guides/understanding-aqi" class="underline">AQI category guide</a> for what each range means for health.
How does Oklahoma County compare to other counties in Oklahoma? ▼
Oklahoma County has 48.2% good air days. Nearby counties in Oklahoma: Adair (59.2% good), Canadian (78.0% good), Carter (80.9% good), Cleveland (53.7% good), Comanche (63.8% good), Creek (80.1% good).
What is the 90th percentile AQI in Oklahoma County? ▼
The 90th percentile AQI for Oklahoma County is 74, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 459 (Hazardous).
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.
Every figure on PlainAir 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.