Median AQI
44
Good
Oklahoma · County air quality · 2025
Canadian County, Oklahoma
Median AQI 44 (Good). 78.0% of monitored days rated Good, direct from EPA Air Quality System stations.
- 44
- Median AQI
- 78.0%
- Good-air days
- 0
- Unhealthy days
- 46%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Canadian County's air is good on balance, more polluted than the median US county, a median AQI of 44 with 78.0% of 214 monitored days in the Good band, driven mainly by Ozone.
- 44
- median AQI · Good
- 78.0%
- days rated Good
- Ozone
- main pollutant
- 46%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 115.
Data updated July 2026
- Good · 167 d · 78.0%
- Moderate · 45 d · 21.0%
- USG · 2 d · 0.9%
How did Canadian County's air break down in 2025?
Across 214 monitored days, 167 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 115 (USG).
EPA AQS →Air quality data from EPA Air Quality System (2025). 214 days monitored. Median AQI: 44 (Good).
Insights: Canadian County, Oklahoma. EPA monitors recorded a median Air Quality Index of 44 across 214 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 167 (78%) fell in the Good band (AQI 0–50), 45 (21%) registered Moderate readings, and 2 (1%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 61, while the worst single-day peak hit 115 (USG). Residents averaged about 23.4 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as Ozone (214 days). Across the 2020–2025 trend window, good days shifted by -165 and the median AQI moved +8 points, placing the multi-year trajectory at worsening. The worst single reading over the 2020–2025 window was AQI 115, usg but never Unhealthy. Nearby counties show comparable readings: Adair (59.2% good, AQI 45); Carter (80.9% good, AQI 33); Cleveland (53.7% good, AQI 49); Comanche (63.8% good, AQI 45); Creek (80.1% good, AQI 43); Dewey (56.6% good, AQI 49).
Air Quality Summary
Good Days
78.0%
167 of 214 monitored days
3.0pp vs 75% target
Max AQI Recorded
115
USG
Health Grade
Good
90th-pct AQI 61
Canadian County, Good days share 78.0%
National avg
Share of monitored days at AQI 0-50 (Good band).
Canadian 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).
AQI Day Breakdown (2025)
Distribution of 214 monitored days across EPA AQI categories.
Good
167
78%
Moderate
45
21%
USG
2
1%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Canadian County.
- Ozone · 214 days · 100.0%
Health Impact Assessment
Good
Canadian County's air quality is rated Good based on 78.0% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 78.0% of monitored days in 2025, with a median AQI of 44. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is Ozone, driving AQI on 214 of 214 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Canadian County. Best year: 2020 (332 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 332 | 26 | 0 | 0 | 36 | 84 |
| 2021 | 292 | 38 | 3 | 0 | 37 | 126 |
| 2022 | 218 | 63 | 3 | 0 | 43 | 108 |
| 2023 | 195 | 77 | 6 | 0 | 45 | 133 |
| 2024 | 204 | 57 | 8 | 0 | 44 | 119 |
| 2025 | 167 | 45 | 2 | 0 | 44 | 115 |
How does Canadian County compare?
How Canadian County compares
Good-day share better than US avg
Canadian County 78.0%
Adair County, Oklahoma 59.2%
US average 76.5%
Median AQI worse than US avg
Canadian County 44
Adair County, Oklahoma 45
US average 38
Unhealthy days / yr about average
Canadian County 0
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 Canadian County.
Baltimore County, Maryland
AQI 44 · 70.4% good
Baltimore (City) County, Maryland
AQI 44 · 68.7% good
Bartholomew County, Indiana
AQI 44 · 69.2% good
Berks County, Pennsylvania
AQI 44 · 65.6% good
Bolivar County, Mississippi
AQI 44 · 70.3% good
Brewster County, Texas
AQI 44 · 69.0% good
What Canadian County's air means for you
The air here stays in the breathable range year-round, with Ozone the main thing to watch.
- Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-Ozone days, the guide explains what a median of 44 means for exposure. Health guidance
- See how Canadian County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Canadian County with its Oklahoma neighbours before drawing a conclusion about the region. All of Oklahoma
Based on 214 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 Canadian County, Oklahoma? ▼
Canadian County has a median Air Quality Index (AQI) of 44, rated "Good." 78.0% of monitored days (167 out of 214) had good air quality in 2025.
What is the main pollutant in Canadian County? ▼
The primary pollutant in Canadian County is Ozone (O3), which was the main AQI driver on 214 days (100% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does Canadian County have? ▼
In 2025, Canadian County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 115.
Is the air quality in Canadian County getting better or worse? ▼
Air quality in Canadian County is worsening based on 5-year trends (2020-2025). Best year: 2020 with 332 good days. Worst year: 2025 with 167 good days.
What does AQI 44 mean for health? ▼
Canadian County's median AQI of 44 falls in the "Good" category. See the <a href="/guides/understanding-aqi" class="underline">AQI category guide</a> for what each range means for health.
How does Canadian County compare to other counties in Oklahoma? ▼
Canadian County has 78.0% good air days. Nearby counties in Oklahoma: Adair (59.2% good), Carter (80.9% good), Cleveland (53.7% good), Comanche (63.8% good), Creek (80.1% good), Dewey (56.6% good).
What is the 90th percentile AQI in Canadian County? ▼
The 90th percentile AQI for Canadian County is 61, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 115 (USG).
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.