Metro area air quality · 2025
Winona, MN
Median AQI 21 (Good). 83.8% of monitored days rated Good across this metro's EPA monitoring network.
- 21
- Median AQI
- 83.8%
- Good-air days
- 0
- Unhealthy days
Winona, MN posted a 2025 median AQI of 21 (Good) with 83.8% Good days
According to the U.S. EPA Air Quality System, the Winona, MN CBSA recorded a median AQI of 21 across 99 monitored days in 2025, with 83.8% 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
- Kahului-Wailuku-Lahaina, HI (98.1% Good, median AQI 21) is the closest nationwide median-AQI peer to Winona, MN.
- 2020–2025 Good-day shift
- Winona, MN's Good-day share moved -10.3 points from 2020 to 2025 (median AQI -1).
- Median AQI
- Median AQI: 21
- Good days
- Good days: 83.8%
Aggregated from EPA Air Quality System (2025), 99 monitored days. EPA AQS →
The verdict
Winona, MN sits in the upper Good-day tercile among EPA CBSA metros on this site (83.8% of 99 monitored days). On the EPA scale the metro runs good, with a median AQI of 21 and 83.8% of 99 monitored days in the Good band.
- 21
- median AQI · Good
- 83.8%
- days rated Good
- 89
- 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
- Winona, MN metro's Good-day share rose from 80.5% to 93.4% between the 2023 and 2024 EPA annual releases, a change of +12.9 percentage points.
- Winona, MN metro's peak single-day AQI fell from 169 to 63 between the 2023 and 2024 EPA annual releases, a change of -106 points.
- Winona, MN metro's median AQI fell from 28 to 20 between the 2023 and 2024 EPA annual releases, a change of -8 points.
- Winona, MN metro's Unhealthy-category days fell from 1 to 0 between the 2023 and 2024 EPA annual releases, a change of -1 days.
Winona, MN sits in the upper Good-day tercile among EPA CBSA metros on this site (83.8% of 99 monitored days). Signature read: 83.8% 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 21 over 99 measured days in 2025 (Good / Good). The monitored-day split lands at 83 Good (84%), 16 Moderate (16%), and 0 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 55; the highest single-day reading hit 89 (Moderate).
Across 2020–2025, Good-day share shifted -10.3 points and median AQI moved -1 (stable). No Unhealthy-tier days appear in this annual dataset. Metros with comparable AQI profiles include Kahului-Wailuku-Lahaina, HI (98.1% good, AQI 21); Othello, WA (90.5% good, AQI 21); Palatka, FL (95.6% good, AQI 21).
Air Quality Summary
Median AQI
21
Good
Good Days
83.8%
83 of 99 days
Max AQI
89
Moderate
Health Grade
Good
90th pct: 55
AQI Day Breakdown (2025)
Distribution of 99 monitored days across EPA AQI categories.
Good
83
84%
Moderate
16
16%
USG
0
0%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Health Impact Assessment
The Winona, MN metro area's air quality is rated Good based on 83.8% 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 Winona, MN metro compare?
How Winona, MN compares
5-Year Air Quality Trend
Air quality is stable in the Winona, MN metro. Highest Good-day share: 2020 (94.1%, 112 of 119 monitored days).
| Year | Good | Moderate | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|
| 2020 | 112 | 7 | 0 | 22 | 57 |
| 2021 | 101 | 15 | 0 | 24 | 80 |
| 2022 | 113 | 8 | 0 | 22 | 65 |
| 2023 | 95 | 22 | 1 | 28 | 169 |
| 2024 | 114 | 8 | 0 | 20 | 63 |
| 2025 | 83 | 16 | 0 | 21 | 89 |
Metros with a similar median AQI
CBSA peers nationwide whose annual median AQI sits near Winona, MN (21).
Kahului-Wailuku-Lahaina, HI
Median AQI 21 · 98.1% Good-day share
Othello, WA
Median AQI 21 · 90.5% Good-day share
Palatka, FL
Median AQI 21 · 95.6% Good-day share
Aberdeen, WA
Median AQI 22 · 97.3% Good-day share
Bremerton-Silverdale, WA
Median AQI 22 · 95.5% Good-day share
Centralia, WA
Median AQI 20 · 91.3% Good-day share
Metros with similar unhealthy-day exposure
A second relationship type: metros whose unhealthy-or-worse day count is closest to Winona, MN's 0 (independent of median AQI).
Aberdeen, SD
0 unhealthy-or-worse days · median AQI 27
Adrian, MI
0 unhealthy-or-worse days · median AQI 41
Akron, OH
0 unhealthy-or-worse days · median AQI 45
Albany, GA
0 unhealthy-or-worse days · median AQI 46
Albany, OR
0 unhealthy-or-worse days · median AQI 27
Albany-Schenectady-Troy, NY
0 unhealthy-or-worse days · median AQI 41
Frequently Asked Questions
How many unhealthy air days does Winona, MN have? ▼
What is the air quality in the Winona, MN metro area? ▼
Is air quality in Winona, MN getting better or worse? ▼
What does AQI 21 mean for health? ▼
How does Winona, MN compare to other metro areas? ▼
What is the 90th percentile AQI for Winona, MN? ▼
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset for Winona, MN, 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, Winona, MN · 2020–2025