Median AQI
40
Good
Michigan · County air quality · 2025
Kalamazoo County, Michigan
Median AQI 40 (Good). 74.0% of monitored days rated Good, direct from EPA Air Quality System stations.
- 40
- Median AQI
- 74.0%
- Good-air days
- 0
- Unhealthy days
- 39%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Kalamazoo County's air is good on balance, more polluted than the median US county, a median AQI of 40 with 74.0% of 304 monitored days in the Good band, driven mainly by Ozone.
- 40
- median AQI · Good
- 74.0%
- days rated Good
- Ozone
- main pollutant
- 39%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 133.
Data updated July 2026
- Good · 225 d · 74.0%
- Moderate · 75 d · 24.7%
- USG · 4 d · 1.3%
How did Kalamazoo County's air break down in 2025?
Across 304 monitored days, 225 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 133 (USG).
EPA AQS →Air quality data from EPA Air Quality System (2025). 304 days monitored. Median AQI: 40 (Good).
Insights: Kalamazoo County, Michigan. EPA monitors recorded a median Air Quality Index of 40 across 304 measured days in 2025, earning a Good classification and a Moderate health grade. Of those days, 225 (74%) fell in the Good band (AQI 0–50), 75 (25%) registered Moderate readings, and 4 (1%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 64, while the worst single-day peak hit 133 (USG). Residents averaged about 22.2 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as Ozone (183 days), PM2.5 (121 days). Across the 2020–2025 trend window, good days shifted by -14 and the median AQI moved -1 points, placing the multi-year trajectory at stable. The worst single reading over the 2020–2025 window was AQI 133, usg but never Unhealthy. Nearby counties show comparable readings: Allegan (71.2% good, AQI 43); Bay (71.8% good, AQI 38); Benzie (91.1% good, AQI 35); Berrien (80.9% good, AQI 41); Cass (85.3% good, AQI 40); Clinton (90.2% good, AQI 39).
Air Quality Summary
Good Days
74.0%
225 of 304 monitored days
-1.0pp vs 75% target
Max AQI Recorded
133
USG
Health Grade
Moderate
90th-pct AQI 64
Kalamazoo County, Good days share 74.0%
National avg
Share of monitored days at AQI 0-50 (Good band).
Kalamazoo 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 304 monitored days across EPA AQI categories.
Good
225
74%
Moderate
75
25%
USG
4
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 Kalamazoo County.
- Ozone · 183 days · 60.2%
- PM2.5 · 121 days · 39.8%
Health Impact Assessment
Moderate
Kalamazoo County's air quality is rated Moderate based on 74.0% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 74.0% of monitored days in 2025, with a median AQI of 40. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is Ozone, driving AQI on 183 of 304 monitored days.
5-Year Air Quality Trend
Air quality is stable in Kalamazoo County. Best year: 2020 (239 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 239 | 78 | 6 | 0 | 41 | 115 |
| 2021 | 177 | 172 | 0 | 0 | 50 | 100 |
| 2022 | 177 | 172 | 3 | 0 | 50 | 134 |
| 2023 | 151 | 198 | 6 | 2 | 53 | 225 |
| 2024 | 234 | 132 | 0 | 0 | 45 | 100 |
| 2025 | 225 | 75 | 4 | 0 | 40 | 133 |
How does Kalamazoo County compare?
How Kalamazoo County compares
Good-day share worse than US avg
Kalamazoo County 74.0%
Allegan County, Michigan 71.2%
US average 76.5%
Median AQI worse than US avg
Kalamazoo County 40
Allegan County, Michigan 43
US average 38
Unhealthy days / yr about average
Kalamazoo County 0
Allegan County, Michigan 1
US average 0
Other Counties in Michigan
Air quality comparison for nearby counties in Michigan.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Kalamazoo County.
Amador County, California
AQI 40 · 84.8% good
Anne Arundel County, Maryland
AQI 40 · 87.2% good
Arlington County, Virginia
AQI 40 · 84.8% good
Bergen County, New Jersey
AQI 40 · 71.1% good
Berkeley County, West Virginia
AQI 40 · 81.1% good
Billings County, North Dakota
AQI 40 · 80.3% good
What Kalamazoo 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 40 means for exposure. Health guidance
- See how Kalamazoo County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Kalamazoo County with its Michigan neighbours before drawing a conclusion about the region. All of Michigan
Based on 304 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 Kalamazoo County, Michigan? ▼
Kalamazoo County has a median Air Quality Index (AQI) of 40, rated "Good." 74.0% of monitored days (225 out of 304) had good air quality in 2025.
What is the main pollutant in Kalamazoo County? ▼
The primary pollutant in Kalamazoo County is Ozone (O3), which was the main AQI driver on 183 days (60% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does Kalamazoo County have? ▼
In 2025, Kalamazoo County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 133.
Is the air quality in Kalamazoo County getting better or worse? ▼
Air quality in Kalamazoo County is stable based on 5-year trends (2020-2025). Best year: 2020 with 239 good days. Worst year: 2023 with 151 good days.
What does AQI 40 mean for health? ▼
Kalamazoo County's median AQI of 40 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 Kalamazoo County compare to other counties in Michigan? ▼
Kalamazoo County has 74.0% good air days. Nearby counties in Michigan: Allegan (71.2% good), Bay (71.8% good), Benzie (91.1% good), Berrien (80.9% good), Cass (85.3% good), Clinton (90.2% good).
What is the 90th percentile AQI in Kalamazoo County? ▼
The 90th percentile AQI for Kalamazoo County is 64, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 133 (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.