Metro area air quality · 2025
Marquette, MI
Median AQI 19 (Good). 82.4% of monitored days rated Good across this metro's EPA monitoring network.
- 19
- Median AQI
- 82.4%
- Good-air days
- 6
- Unhealthy days
- 72%
- Cleaner than US metros
Marquette, MI posted a 2025 median AQI of 19 (Good) with 82.4% Good days
According to the U.S. EPA Air Quality System, the Marquette, MI CBSA recorded a median AQI of 19 across 307 monitored days in 2025, with 82.4% rated Good and 6 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 Marquette, MI CBSA's 82.4% Good-day share places it cleaner than 72% of US metros in 2025.
- Closest median-AQI peer
- Centralia, WA (91.3% Good, median AQI 20) is the closest nationwide median-AQI peer to Marquette, MI.
- 2024–2025 Good-day shift
- Marquette, MI's Good-day share moved -5.8 points from 2024 to 2025 (median AQI +0).
- Median AQI
- Median AQI: 19
Aggregated from EPA Air Quality System (2025), 307 monitored days. EPA AQS →
The verdict
Marquette, MI sits in the upper Good-day tercile among EPA CBSA metros on this site (82.4% of 307 monitored days). On the EPA scale the metro runs good, cleaner than the median US metro, with a median AQI of 19 and 82.4% of 307 monitored days in the Good band.
- 19
- median AQI · Good
- 82.4%
- days rated Good
- 72%
- cleaner than US metros
- 193
- worst single reading
6 days reached Unhealthy or worse across the metro's monitors in 2025.
Annual release change
What changed in the 2025 EPA annual release
- Marquette, MI metro's peak single-day AQI rose from 67 to 193 between the 2024 and 2025 EPA annual releases, a change of +126 points.
- Marquette, MI metro's Unhealthy-category days rose from 0 to 6 between the 2024 and 2025 EPA annual releases, a change of +6 days.
- Marquette, MI metro's Good-day share fell from 90.2% to 84.3% between the 2024 and 2025 EPA annual releases, a change of -5.8 percentage points.
Marquette, MI sits in the upper Good-day tercile among EPA CBSA metros on this site (82.4% of 307 monitored days). Signature read: 82.4% Good-day share (high tercile vs CBSA corpus). Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 19 over 307 measured days in 2025 (Good / Good). The monitored-day split lands at 253 Good (82%), 41 Moderate (13%), and 7 Unhealthy-for-Sensitive-Groups (2%). The 90th-percentile AQI finished at 62; the highest single-day reading hit 193 (Unhealthy).
Across 2024–2025, Good-day share shifted -5.8 points and median AQI moved +0 (worsening). The annual record contains 6 days at Unhealthy or worse. Metros with comparable AQI profiles include Centralia, WA (91.3% good, AQI 20); Pierre, SD (93.0% good, AQI 18); Deming, NM (84.7% good, AQI 17).
Air Quality Summary
Median AQI
19
Good
Good Days
82.4%
253 of 307 days
Max AQI
193
Unhealthy
Health Grade
Good
90th pct: 62
AQI Day Breakdown (2025)
Distribution of 307 monitored days across EPA AQI categories.
Good
253
82%
Moderate
41
13%
USG
7
2%
Unhealthy
6
2%
Very Unhealthy
0
0%
Hazardous
0
0%
Health Impact Assessment
The Marquette, MI metro area's air quality is rated Good based on 82.4% good air days. There were 6 unhealthy days in 2025 when outdoor activity should be limited.
Air quality is acceptable most days, but 7 days reached "Unhealthy for Sensitive Groups" and peak AQI reached 193. Sensitive groups should monitor real-time conditions at AirNow.gov.
How does the Marquette, MI metro compare?
How Marquette, MI compares
5-Year Air Quality Trend
Air quality is worsening in the Marquette, MI metro. Highest Good-day share: 2024 (90.2%, 202 of 224 monitored days).
| Year | Good | Moderate | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|
| 2024 | 202 | 22 | 0 | 19 | 67 |
| 2025 | 253 | 41 | 6 | 19 | 193 |
Metros with a similar median AQI
CBSA peers nationwide whose annual median AQI sits near Marquette, MI (19).
Centralia, WA
Median AQI 20 · 91.3% Good-day share
Pierre, SD
Median AQI 18 · 93.0% Good-day share
Deming, NM
Median AQI 17 · 84.7% Good-day share
Hailey, ID
Median AQI 17 · 96.6% Good-day share
Kahului-Wailuku-Lahaina, HI
Median AQI 21 · 98.1% Good-day share
Lake Havasu City-Kingman, AZ
Median AQI 17 · 94.8% Good-day share
Metros with similar unhealthy-day exposure
A second relationship type: metros whose unhealthy-or-worse day count is closest to Marquette, MI's 6 (independent of median AQI).
Appleton, WI
6 unhealthy-or-worse days · median AQI 38
Chicago-Naperville-Elgin, IL-IN-WI
6 unhealthy-or-worse days · median AQI 56
Minneapolis-St. Paul-Bloomington, MN-WI
6 unhealthy-or-worse days · median AQI 47
Spokane-Spokane Valley, WA
6 unhealthy-or-worse days · median AQI 47
Dallas-Fort Worth-Arlington, TX
5 unhealthy-or-worse days · median AQI 59
Eau Claire, WI
5 unhealthy-or-worse days · median AQI 38
Frequently Asked Questions
How many unhealthy air days does Marquette, MI have? ▼
What is the air quality in the Marquette, MI metro area? ▼
Is air quality in Marquette, MI getting better or worse? ▼
What does AQI 19 mean for health? ▼
How does Marquette, MI compare to other metro areas? ▼
What is the 90th percentile AQI for Marquette, MI? ▼
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset for Marquette, 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, Marquette, MI · 2020–2025