Median AQI
24
Good
Idaho · County air quality · 2025
Kootenai County, Idaho
Median AQI 24 (Good). 88.4% of monitored days rated Good, direct from EPA Air Quality System stations.
- 24
- Median AQI
- 88.4%
- Good-air days
- 0
- Unhealthy days
- 72%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Kootenai County's air is good on balance, cleaner than the median US county, a median AQI of 24 with 88.4% of 181 monitored days in the Good band, driven mainly by PM2.5.
- 24
- median AQI · Good
- 88.4%
- days rated Good
- PM2.5
- main pollutant
- 72%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 71.
Data updated July 2026
- Good · 160 d · 88.4%
- Moderate · 21 d · 11.6%
How did Kootenai County's air break down in 2025?
Across 181 monitored days, 160 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 71 (Moderate).
EPA AQS →Air quality data from EPA Air Quality System (2025). 181 days monitored. Median AQI: 24 (Good).
Insights: Kootenai County, Idaho. EPA monitors recorded a median Air Quality Index of 24 across 181 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 160 (88%) fell in the Good band (AQI 0–50), 21 (12%) 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 71 (Moderate). Residents averaged about 26.5 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 -128 and the median AQI moved -2 points, placing the multi-year trajectory at improving. The worst single reading over the 2020–2025 window was AQI 71, moderate but never Unhealthy. Nearby counties show comparable readings: Ada (80.6% good, AQI 39); Bannock (91.5% good, AQI 31); Benewah (74.6% good, AQI 37); Blaine (99.4% good, AQI 22); Boise (72.9% good, AQI 43); Bonner (71.3% good, AQI 41).
Air Quality Summary
Good Days
88.4%
160 of 181 monitored days
13.4pp vs 75% target
Max AQI Recorded
71
Moderate
Health Grade
Good
90th-pct AQI 52
Kootenai County, Good days share 88.4%
National avg
Share of monitored days at AQI 0-50 (Good band).
Kootenai 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
160
88%
Moderate
21
12%
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 Kootenai County.
- PM2.5 · 181 days · 100.0%
Health Impact Assessment
Good
Kootenai County's air quality is rated Good based on 88.4% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 88.4% of monitored days in 2025, with a median AQI of 24. 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 Kootenai County. Best year: 2024 (291 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 288 | 58 | 1 | 2 | 26 | 518 |
| 2021 | 268 | 81 | 3 | 5 | 31 | 195 |
| 2022 | 264 | 88 | 4 | 3 | 29 | 186 |
| 2023 | 279 | 78 | 2 | 1 | 32 | 222 |
| 2024 | 291 | 63 | 1 | 0 | 24 | 109 |
| 2025 | 160 | 21 | 0 | 0 | 24 | 71 |
How does Kootenai County compare?
How Kootenai County compares
Good-day share better than US avg
Kootenai County 88.4%
Ada County, Idaho 80.6%
US average 76.5%
Median AQI better than US avg
Kootenai County 24
Ada County, Idaho 39
US average 38
Unhealthy days / yr about average
Kootenai County 0
Ada County, Idaho 0
US average 0
Other Counties in Idaho
Air quality comparison for nearby counties in Idaho.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Kootenai County.
Alamosa County, Colorado
AQI 24 · 90.8% good
Anchorage County, Alaska
AQI 24 · 80.8% good
Charlton County, Georgia
AQI 24 · 79.0% good
Crook County, Oregon
AQI 24 · 80.7% good
Culberson County, Texas
AQI 24 · 80.0% good
Lake County, Oregon
AQI 24 · 82.8% good
What Kootenai 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 24 means for exposure. Health guidance
- See how Kootenai County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Kootenai County with its Idaho neighbours before drawing a conclusion about the region. All of Idaho
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 Kootenai County, Idaho? ▼
Kootenai County has a median Air Quality Index (AQI) of 24, rated "Good." 88.4% of monitored days (160 out of 181) had good air quality in 2025.
What is the main pollutant in Kootenai County? ▼
The primary pollutant in Kootenai 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 Kootenai County have? ▼
In 2025, Kootenai County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 71.
Is the air quality in Kootenai County getting better or worse? ▼
Air quality in Kootenai County is improving based on 5-year trends (2020-2025). Best year: 2024 with 291 good days. Worst year: 2025 with 160 good days.
What does AQI 24 mean for health? ▼
Kootenai County's median AQI of 24 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 Kootenai County compare to other counties in Idaho? ▼
Kootenai County has 88.4% good air days. Nearby counties in Idaho: Ada (80.6% good), Bannock (91.5% good), Benewah (74.6% good), Blaine (99.4% good), Boise (72.9% good), Bonner (71.3% good).
What is the 90th percentile AQI in Kootenai County? ▼
The 90th percentile AQI for Kootenai County is 52, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 71 (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.