Metro area air quality · 2025

Rochester, MN

Median AQI 39 (Good). 69.5% of monitored days rated Good across this metro's EPA monitoring network.

39
Median AQI
69.5%
Good-air days
3
Unhealthy days
44%
Cleaner than US metros

Rochester, MN posted a 2025 median AQI of 39 (Good) with 69.5% Good days

According to the U.S. EPA Air Quality System, the Rochester, MN CBSA recorded a median AQI of 39 across 344 monitored days in 2025, with 69.5% rated Good and 3 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 Rochester, MN CBSA's 69.5% Good-day share places it cleaner than 44% of US metros in 2025.
Closest median-AQI peer
Bay City, MI (70.4% Good, median AQI 39) is the closest nationwide median-AQI peer to Rochester, MN.
2020–2025 Good-day shift
Rochester, MN's Good-day share moved -9.5 points from 2020 to 2025 (median AQI +1).
Median AQI
Median AQI: 39

Aggregated from EPA Air Quality System (2025), 344 monitored days. EPA AQS →

The verdict

Rochester, MN's peak reading 166 is in the upper max-AQI tercile among CBSA metros here. On the EPA scale the metro runs good, more polluted than the median US metro, with a median AQI of 39 and 69.5% of 344 monitored days in the Good band.

39
median AQI · Good
69.5%
days rated Good
44%
cleaner than US metros
166
worst single reading

3 days reached Unhealthy or worse across the metro's monitors in 2025.

Annual release change

What changed in the 2025 EPA annual release

2024 → 2025
  • Rochester, MN metro's Good-day share rose from 63.9% to 70.5% between the 2024 and 2025 EPA annual releases, a change of +6.6 percentage points.
  • Rochester, MN metro's Unhealthy-category days rose from 1 to 3 between the 2024 and 2025 EPA annual releases, a change of +2 days.
  • Rochester, MN metro's median AQI fell from 44 to 39 between the 2024 and 2025 EPA annual releases, a change of -5 points.
  • Rochester, MN metro's peak single-day AQI rose from 155 to 166 between the 2024 and 2025 EPA annual releases, a change of +11 points.

Compared against 366 monitored days in 2024 and 339 in 2025. These are arithmetic differences between two stored EPA annual summaries, not a cause claim or a live advisory.

National release changes Two-year CSV

Rochester, MN's peak reading 166 is in the upper max-AQI tercile among CBSA metros here. Signature read: peak AQI 166 (high tercile vs CBSA corpus). Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 39 over 344 measured days in 2025 (Good / Moderate). The monitored-day split lands at 239 Good (69%), 97 Moderate (28%), and 5 Unhealthy-for-Sensitive-Groups (1%). The 90th-percentile AQI finished at 65; the highest single-day reading hit 166 (Unhealthy).

Across 2020–2025, Good-day share shifted -9.5 points and median AQI moved +1 (worsening). The annual record contains 3 days at Unhealthy or worse. Metros with comparable AQI profiles include Bay City, MI (70.4% good, AQI 39); Brainerd, MN (74.3% good, AQI 39); Cambridge, MD (86.0% good, AQI 39).

Health effects of air pollution →

Air Quality Summary

Median AQI

39

Good

Good Days

69.5%

239 of 344 days

Max AQI

166

Unhealthy

Health Grade

Moderate

90th pct: 65

AQI Day Breakdown (2025)

Distribution of 344 monitored days across EPA AQI categories.

Good

239

69%

Moderate

97

28%

USG

5

1%

Unhealthy

3

1%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Moderate

The Rochester, MN metro area's air quality is rated Moderate based on 69.5% good air days. There were 3 unhealthy days in 2025 when outdoor activity should be limited.

Air quality is acceptable most days, but 5 days reached "Unhealthy for Sensitive Groups" and peak AQI reached 166. Sensitive groups should monitor real-time conditions at AirNow.gov.

How does the Rochester, MN metro compare?

How Rochester, MN compares

Good-day share worse than typical
Rochester, MN 69.5%
Bay City, MI 70.4%
Typical US metro 70.6%
Median AQI better than typical
Rochester, MN 39
Bay City, MI 39
Typical US metro 41
Unhealthy days / yr worse than typical
Rochester, MN 3
Bay City, MI 0
Typical US metro 1

5-Year Air Quality Trend

Air quality is worsening in the Rochester, MN metro. Highest Good-day share: 2020 (80.0%, 292 of 365 monitored days).

Year Good Moderate Unhealthy Median AQI
2020 292 73 0 38
2021 275 84 0 39
2022 280 78 0 41
2023 189 161 1 49
2024 234 131 1 44
2025 239 97 3 39

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near Rochester, MN (39).

Metros with similar unhealthy-day exposure

A second relationship type: metros whose unhealthy-or-worse day count is closest to Rochester, MN's 3 (independent of median AQI).

Frequently Asked Questions

What is the 90th percentile AQI for Rochester, MN?
The 90th percentile AQI for the Rochester, MN metro area is 65, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 166 (Unhealthy).
How many unhealthy air days does Rochester, MN have?
In 2025, the Rochester, MN metro area recorded 3 unhealthy air days (3 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 166.
What is the air quality in the Rochester, MN metro area?
The Rochester, MN metro area has a median Air Quality Index (AQI) of 39, rated "Good." 69.5% of monitored days (239 out of 344) had good air quality in 2025.
Is air quality in Rochester, MN getting better or worse?
Air quality in the Rochester, MN metro is worsening across floor-qualifying years (2020-2025); years with fewer than 100 monitored days are excluded from that direction. Highest qualifying Good-day share: 2020 at 80.0% (292 of 365 days). Lowest qualifying Good-day share: 2023 at 53.8% (189 of 351 days).
What does AQI 39 mean for health?
An AQI of 39 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 Rochester, MN compare to other metro areas?
The Rochester, MN metro has 69.5% good air days. Similar metros: Bay City, MI (70.4% good), Brainerd, MN (74.3% good), Cambridge, MD (86.0% good).

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset for Rochester, MN, 2025. See our methodology for how AQI, median, and coverage figures are computed.

Source: U.S. EPA Air Quality System (AQS) Annual AQI by CBSA summary, Rochester, MN · 2020–2025