Median AQI
25
Good
Oregon · County air quality · 2025
Baker County, Oregon
Median AQI 25 (Good). 89.0% of monitored days rated Good, direct from EPA Air Quality System stations.
- 25
- Median AQI
- 89.0%
- Good-air days
- 0
- Unhealthy days
- 74%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Baker County's air is good on balance, cleaner than the median US county, a median AQI of 25 with 89.0% of 181 monitored days in the Good band, driven mainly by PM2.5.
- 25
- median AQI · Good
- 89.0%
- days rated Good
- PM2.5
- main pollutant
- 74%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 68.
Data updated July 2026
- Good · 161 d · 89.0%
- Moderate · 20 d · 11.0%
How did Baker County's air break down in 2025?
Across 181 monitored days, 161 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 68 (Moderate).
EPA AQS →Air quality data from EPA Air Quality System (2025). 181 days monitored. Median AQI: 25 (Good).
Insights: Baker County, Oregon. EPA monitors recorded a median Air Quality Index of 25 across 181 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 161 (89%) fell in the Good band (AQI 0–50), 20 (11%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 52, while the worst single-day peak hit 68 (Moderate). Residents averaged about 26.7 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (181 days). Across the 2020–2025 trend window, good days shifted by -121 and the median AQI moved -8 points, placing the multi-year trajectory at improving. The worst single reading over the 2020–2025 window was AQI 68, moderate but never Unhealthy. Nearby counties show comparable readings: Clackamas (93.9% good, AQI 27); Columbia (96.7% good, AQI 25); Crook (80.7% good, AQI 24); Deschutes (93.4% good, AQI 22); Grant (66.7% good, AQI 34); Harney (70.7% good, AQI 26).
Air Quality Summary
Good Days
89.0%
161 of 181 monitored days
14.0pp vs 75% target
Max AQI Recorded
68
Moderate
Health Grade
Good
90th-pct AQI 52
Baker County, Good days share 89.0%
National avg
Share of monitored days at AQI 0-50 (Good band).
Baker 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 181 monitored days across EPA AQI categories.
Good
161
89%
Moderate
20
11%
USG
0
0%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Baker County.
- PM2.5 · 181 days · 100.0%
Health Impact Assessment
Good
Baker County's air quality is rated Good based on 89.0% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 89.0% of monitored days in 2025, with a median AQI of 25. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is PM2.5, driving AQI on 181 of 181 monitored days.
5-Year Air Quality Trend
Air quality is improving in Baker County. Best year: 2023 (301 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 282 | 77 | 2 | 3 | 33 | 225 |
| 2021 | 271 | 88 | 1 | 4 | 29 | 155 |
| 2022 | 283 | 79 | 3 | 0 | 32 | 124 |
| 2023 | 301 | 62 | 0 | 0 | 30 | 83 |
| 2024 | 279 | 84 | 1 | 2 | 28 | 155 |
| 2025 | 161 | 20 | 0 | 0 | 25 | 68 |
How does Baker County compare?
How Baker County compares
Good-day share better than US avg
Baker County 89.0%
Clackamas County, Oregon 93.9%
US average 76.5%
Median AQI better than US avg
Baker County 25
Clackamas County, Oregon 27
US average 38
Unhealthy days / yr about average
Baker County 0
Clackamas County, Oregon 0
US average 0
Other Counties in Oregon
Air quality comparison for nearby counties in Oregon.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Baker County.
Brown County, South Dakota
AQI 25 · 87.1% good
Columbia County, Oregon
AQI 25 · 96.7% good
Fremont County, Colorado
AQI 25 · 91.1% good
Lubbock County, Texas
AQI 25 · 89.9% good
Sherman County, Kansas
AQI 25 · 86.6% good
Walla Walla County, Washington
AQI 25 · 86.0% good
What Baker County's air means for you
The air here stays in the breathable range year-round, with PM2.5 the main thing to watch.
- Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-PM2.5 days, the guide explains what a median of 25 means for exposure. Health guidance
- See how Baker County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Baker County with its Oregon neighbours before drawing a conclusion about the region. All of Oregon
Based on 181 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 Baker County, Oregon? ▼
Baker County has a median Air Quality Index (AQI) of 25, rated "Good." 89.0% of monitored days (161 out of 181) had good air quality in 2025.
What is the main pollutant in Baker County? ▼
The primary pollutant in Baker County is Fine Particles (PM2.5), which was the main AQI driver on 181 days (100% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Baker County have? ▼
In 2025, Baker County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 68.
Is the air quality in Baker County getting better or worse? ▼
Air quality in Baker County is improving based on 5-year trends (2020-2025). Best year: 2023 with 301 good days. Worst year: 2025 with 161 good days.
What does AQI 25 mean for health? ▼
Baker County's median AQI of 25 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 Baker County compare to other counties in Oregon? ▼
Baker County has 89.0% good air days. Nearby counties in Oregon: Clackamas (93.9% good), Columbia (96.7% good), Crook (80.7% good), Deschutes (93.4% good), Grant (66.7% good), Harney (70.7% good).
What is the 90th percentile AQI in Baker County? ▼
The 90th percentile AQI for Baker County is 52, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 68 (Moderate).
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.