Metro area air quality · 2025
Kalamazoo-Portage, MI
Median AQI 43 (Good). 61.4% of monitored days rated Good across this metro's EPA monitoring network.
- 43
- Median AQI
- 61.4%
- Good-air days
- 1
- Unhealthy days
- 27%
- Cleaner than US metros
Kalamazoo-Portage, MI posted a 2025 median AQI of 43 (Good) with 61.4% Good days
According to the U.S. EPA Air Quality System, the Kalamazoo-Portage, MI CBSA recorded a median AQI of 43 across 365 monitored days in 2025, with 61.4% rated Good and 1 unhealthy or worse. This is an annual metro comparison, not a live advisory.
Data source EPA Air Quality System (AQS)
- Cleaner than US metros
- The Kalamazoo-Portage, MI CBSA's 61.4% Good-day share places it cleaner than 27% of US metros in 2025.
- Closest median-AQI peer
- Ashtabula, OH (81.2% Good, median AQI 43) is the closest nationwide median-AQI peer to Kalamazoo-Portage, MI.
- 2020–2025 Good-day shift
- Kalamazoo-Portage, MI's Good-day share moved -13.0 points from 2020 to 2025 (median AQI +2).
- Median AQI
- Median AQI: 43
Aggregated from EPA Air Quality System (2025), 365 monitored days. EPA AQS →
The verdict
Kalamazoo-Portage, MI lands in the lower Good-day tercile (61.4% Good), a thinner clean-air share than most CBSA peers here. On the EPA scale the metro runs good, more polluted than the median US metro, with a median AQI of 43 and 61.4% of 365 monitored days in the Good band.
- 43
- median AQI · Good
- 61.4%
- days rated Good
- 27%
- cleaner than US metros
- 156
- worst single reading
1 day reached Unhealthy or worse across the metro's monitors in 2025.
Annual release change
What changed in the 2025 EPA annual release
- Kalamazoo-Portage, MI metro's peak single-day AQI rose from 100 to 156 between the 2024 and 2025 EPA annual releases, a change of +56 points.
- Kalamazoo-Portage, MI metro's Good-day share fell from 63.9% to 62.4% between the 2024 and 2025 EPA annual releases, a change of -1.5 percentage points.
- Kalamazoo-Portage, MI metro's Unhealthy-category days rose from 0 to 1 between the 2024 and 2025 EPA annual releases, a change of +1 days.
Kalamazoo-Portage, MI lands in the lower Good-day tercile (61.4% Good), a thinner clean-air share than most CBSA peers here. Signature read: 61.4% Good-day share (low tercile vs CBSA corpus). Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 43 over 365 measured days in 2025 (Good / Moderate). The monitored-day split lands at 224 Good (61%), 134 Moderate (37%), and 6 Unhealthy-for-Sensitive-Groups (2%). The 90th-percentile AQI finished at 71; the highest single-day reading hit 156 (Unhealthy).
Across 2020–2025, Good-day share shifted -13.0 points and median AQI moved +2 (worsening). The annual record contains 1 day at Unhealthy or worse. Metros with comparable AQI profiles include Ashtabula, OH (81.2% good, AQI 43); Bloomington, IN (67.7% good, AQI 43); Champaign-Urbana, IL (65.8% good, AQI 43).
Air Quality Summary
Median AQI
43
Good
Good Days
61.4%
224 of 365 days
Max AQI
156
Unhealthy
Health Grade
Moderate
90th pct: 71
AQI Day Breakdown (2025)
Distribution of 365 monitored days across EPA AQI categories.
Good
224
61%
Moderate
134
37%
USG
6
2%
Unhealthy
1
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Health Impact Assessment
The Kalamazoo-Portage, MI metro area's air quality is rated Moderate based on 61.4% good air days. There were 1 unhealthy days in 2025 when outdoor activity should be limited.
Air quality is acceptable most days, but 6 days reached "Unhealthy for Sensitive Groups" and peak AQI reached 156. Sensitive groups should monitor real-time conditions at AirNow.gov.
How does the Kalamazoo-Portage, MI metro compare?
How Kalamazoo-Portage, MI compares
5-Year Air Quality Trend
Air quality is worsening in the Kalamazoo-Portage, MI metro. Highest Good-day share: 2020 (75.4%, 239 of 317 monitored days).
| Year | Good | Moderate | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|
| 2020 | 239 | 78 | 0 | 41 | 115 |
| 2021 | 177 | 172 | 0 | 50 | 100 |
| 2022 | 177 | 172 | 0 | 50 | 134 |
| 2023 | 151 | 198 | 2 | 53 | 225 |
| 2024 | 234 | 132 | 0 | 45 | 100 |
| 2025 | 224 | 134 | 1 | 43 | 156 |
Metros with a similar median AQI
CBSA peers nationwide whose annual median AQI sits near Kalamazoo-Portage, MI (43).
Ashtabula, OH
Median AQI 43 · 81.2% Good-day share
Bloomington, IN
Median AQI 43 · 67.7% Good-day share
Champaign-Urbana, IL
Median AQI 43 · 65.8% Good-day share
Cleveland, MS
Median AQI 43 · 71.9% Good-day share
Columbus, IN
Median AQI 43 · 72.6% Good-day share
Durham-Chapel Hill, NC
Median AQI 43 · 71.5% Good-day share
Metros with similar unhealthy-day exposure
A second relationship type: metros whose unhealthy-or-worse day count is closest to Kalamazoo-Portage, MI's 1 (independent of median AQI).
Ann Arbor, MI
1 unhealthy-or-worse days · median AQI 41
Bangor, ME
1 unhealthy-or-worse days · median AQI 33
Baraboo, WI
1 unhealthy-or-worse days · median AQI 35
Bartlesville, OK
1 unhealthy-or-worse days · median AQI 44
Beaumont-Port Arthur, TX
1 unhealthy-or-worse days · median AQI 52
Beaver Dam, WI
1 unhealthy-or-worse days · median AQI 40
Frequently Asked Questions
How many unhealthy air days does Kalamazoo-Portage, MI have? ▼
What is the air quality in the Kalamazoo-Portage, MI metro area? ▼
Is air quality in Kalamazoo-Portage, MI getting better or worse? ▼
What does AQI 43 mean for health? ▼
How does Kalamazoo-Portage, MI compare to other metro areas? ▼
What is the 90th percentile AQI for Kalamazoo-Portage, MI? ▼
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset for Kalamazoo-Portage, MI, 2025. See our methodology for how AQI, median, and coverage figures are computed.
Read our methodology , how this data is sourced, computed, and verified.
Source: U.S. EPA Air Quality System (AQS) Annual AQI by CBSA summary, Kalamazoo-Portage, MI · 2020–2025