Metro area air quality · 2025

Houghton, MI

Median AQI 8 (Good). 100.0% of monitored days rated Good across this metro's EPA monitoring network.

8
Median AQI
100.0%
Good-air days
0
Unhealthy days

Houghton, MI posted a 2025 median AQI of 8 (Good) with 100.0% Good days

According to the U.S. EPA Air Quality System, the Houghton, MI CBSA recorded a median AQI of 8 across 41 monitored days in 2025, with 100.0% rated Good and 0 unhealthy or worse. This is an annual metro comparison, not a live advisory.

Data source EPA Air Quality System (AQS)

Closest median-AQI peer
Evanston, WY (100.0% Good, median AQI 9) is the closest nationwide median-AQI peer to Houghton, MI.
2020–2025 Good-day shift
Houghton, MI's Good-day share moved +0.0 points from 2020 to 2025 (median AQI -5).
Median AQI
Median AQI: 8
Good days
Good days: 100.0%

Aggregated from EPA Air Quality System (2025), 41 monitored days. EPA AQS →

The verdict

Houghton, MI sits in the upper Good-day tercile among EPA CBSA metros on this site (100.0% of 41 monitored days). On the EPA scale the metro runs good, with a median AQI of 8 and 100.0% of 41 monitored days in the Good band.

8
median AQI · Good
100.0%
days rated Good
31
worst single reading

No day crossed into the Unhealthy tier across the metro's monitors in 2025.

Annual release change

What changed in the 2024 EPA annual release

2023 → 2024
  • Houghton, MI metro's Good-day share rose from 89.7% to 98.3% between the 2023 and 2024 EPA annual releases, a change of +8.6 percentage points.
  • Houghton, MI metro's peak single-day AQI fell from 141 to 66 between the 2023 and 2024 EPA annual releases, a change of -75 points.
  • Houghton, MI metro's median AQI fell from 16 to 12 between the 2023 and 2024 EPA annual releases, a change of -4 points.

Compared against 117 monitored days in 2023 and 120 in 2024. These are arithmetic differences between two stored EPA annual summaries, not a cause claim or a live advisory.

National release changes Two-year CSV

Houghton, MI sits in the upper Good-day tercile among EPA CBSA metros on this site (100.0% of 41 monitored days). Signature read: 100.0% 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 8 over 41 measured days in 2025 (Good / Excellent). The monitored-day split lands at 41 Good (100%), 0 Moderate (0%), and 0 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 16; the highest single-day reading hit 31 (Good).

Across 2020–2025, Good-day share shifted +0.0 points and median AQI moved -5 (stable). No Unhealthy-tier days appear in this annual dataset. Metros with comparable AQI profiles include Evanston, WY (100.0% good, AQI 9); Mayaguez, PR (97.8% good, AQI 9); Santa Rosa, CA (100.0% good, AQI 9).

Best and worst city air quality →

Air Quality Summary

Median AQI

8

Good

Good Days

100.0%

41 of 41 days

Max AQI

31

Good

Health Grade

Excellent

90th pct: 16

AQI Day Breakdown (2025)

Distribution of 41 monitored days across EPA AQI categories.

Good

41

100%

Moderate

0

0%

USG

0

0%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Excellent

The Houghton, MI metro area's air quality is rated Excellent based on 100.0% good air days. No unhealthy air days were recorded in 2025.

Air quality is generally acceptable. Unusually sensitive people should monitor real-time conditions at AirNow.gov during high-pollution events.

How does the Houghton, MI metro compare?

How Houghton, MI compares

Good-day share better than typical
Houghton, MI 100.0%
Evanston, WY 100.0%
Typical US metro 70.6%
Median AQI better than typical
Houghton, MI 8
Evanston, WY 9
Typical US metro 41
Unhealthy days / yr better than typical
Houghton, MI 0
Evanston, WY 0
Typical US metro 1

5-Year Air Quality Trend

Air quality is stable in the Houghton, MI metro. Highest Good-day share: 2020 (100.0%, 116 of 116 monitored days).

Year Good Moderate Unhealthy Median AQI
2020 116 0 0 13
2021 109 8 0 14
2022 119 3 0 12
2023 105 12 0 16
2024 118 2 0 12
2025 41 0 0 8

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near Houghton, MI (8).

Evanston, WY

Median AQI 9 · 100.0% Good-day share

9

Mayaguez, PR

Median AQI 9 · 97.8% Good-day share

9

Santa Rosa, CA

Median AQI 9 · 100.0% Good-day share

9

Bozeman, MT

Median AQI 11 · 98.1% Good-day share

11

Ponce, PR

Median AQI 3 · 91.4% Good-day share

3

Show Low, AZ

Median AQI 13 · 99.5% Good-day share

13

Metros with similar unhealthy-day exposure

A second relationship type: metros whose unhealthy-or-worse day count is closest to Houghton, MI's 0 (independent of median AQI).

Aberdeen, SD

0 unhealthy-or-worse days · median AQI 27

27

Aberdeen, WA

0 unhealthy-or-worse days · median AQI 22

22

Adrian, MI

0 unhealthy-or-worse days · median AQI 41

41

Akron, OH

0 unhealthy-or-worse days · median AQI 45

45

Albany, GA

0 unhealthy-or-worse days · median AQI 46

46

Albany, OR

0 unhealthy-or-worse days · median AQI 27

27

Frequently Asked Questions

How many unhealthy air days does Houghton, MI have? ▼
In 2025, the Houghton, MI metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 31.
What is the air quality in the Houghton, MI metro area? ▼
The Houghton, MI metro area has a median Air Quality Index (AQI) of 8, rated "Good." 100.0% of monitored days (41 out of 41) had good air quality in 2025.
Is air quality in Houghton, MI getting better or worse? ▼
Air quality in the Houghton, MI metro is stable across floor-qualifying years (2020-2024); years with fewer than 100 monitored days are excluded from that direction. Highest qualifying Good-day share: 2020 at 100.0% (116 of 116 days). Lowest qualifying Good-day share: 2023 at 89.7% (105 of 117 days).
What does AQI 8 mean for health? ▼
An AQI of 8 is "Good", air quality is satisfactory and poses little or no health risk. This is the best category on the EPA's AQI scale.
How does Houghton, MI compare to other metro areas? ▼
The Houghton, MI metro has 100.0% good air days. Similar metros: Evanston, WY (100.0% good), Mayaguez, PR (97.8% good), Santa Rosa, CA (100.0% good).
What is the 90th percentile AQI for Houghton, MI? ▼
The 90th percentile AQI for the Houghton, MI metro area is 16, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 31 (Good).

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset for Houghton, 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, Houghton, MI · 2020–2025