Metro area air quality · 2025
Wausau, WI
Median AQI 36 (Good). 76.6% of monitored days rated Good across this metro's EPA monitoring network.
- 36
- Median AQI
- 76.6%
- Good-air days
- 4
- Unhealthy days
- 60%
- Cleaner than US metros
Wausau, WI posted a 2025 median AQI of 36 (Good) with 76.6% Good days
According to the U.S. EPA Air Quality System, the Wausau, WI CBSA recorded a median AQI of 36 across 342 monitored days in 2025, with 76.6% rated Good and 4 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 Wausau, WI CBSA's 76.6% Good-day share places it cleaner than 60% of US metros in 2025.
- Closest median-AQI peer
- Atlantic City-Hammonton, NJ (82.2% Good, median AQI 36) is the closest nationwide median-AQI peer to Wausau, WI.
- 2020–2025 Good-day shift
- Wausau, WI's Good-day share moved -19.2 points from 2020 to 2025 (median AQI +5).
- Median AQI
- Median AQI: 36
Aggregated from EPA Air Quality System (2025), 342 monitored days. EPA AQS →
The verdict
The Wausau, WI metro runs good on the EPA scale, cleaner than the median US metro, a median AQI of 36 with 76.6% of 342 monitored days in the Good band.
- 36
- median AQI · Good
- 76.6%
- days rated Good
- 60%
- cleaner than US metros
- 168
- worst single reading
4 days reached Unhealthy or worse across the metro's monitors in 2025.
Annual release change
What changed in the 2025 EPA annual release
- Wausau, WI metro's Good-day share fell from 85.0% to 77.7% between the 2024 and 2025 EPA annual releases, a change of -7.2 percentage points.
- Wausau, WI metro's Unhealthy-category days rose from 1 to 4 between the 2024 and 2025 EPA annual releases, a change of +3 days.
- Wausau, WI metro's peak single-day AQI rose from 151 to 168 between the 2024 and 2025 EPA annual releases, a change of +17 points.
Insights: Wausau, WI metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 36 over 342 measured days in 2025, which corresponds to a Good band and a Good metro-wide health grade. The monitored-day split lands at 262 Good days (77%), 71 Moderate (21%), and 5 Unhealthy-for-Sensitive-Groups (1%). The 90th-percentile AQI finished at 61 while the highest single-day reading hit 168 (Unhealthy). Metro residents averaged roughly 23.0 clean-air days per 30-day window across the reporting year.
Across the 2020–2025 trend window, the share of monitored days rated Good shifted by -19.2 points (measured against 199 monitored days in 2020 and 337 in 2025, so raw day counts are not comparable) and the median AQI moved +5 points, which classifies the multi-year trajectory as worsening. The annual record contains 4 days at Unhealthy or worse. On those days, the EPA recommends that sensitive groups limit prolonged outdoor exertion. Metros with comparable AQI profiles include Atlantic City-Hammonton, NJ (82.2% good, AQI 36); Barnstable Town, MA (93.7% good, AQI 36); Bemidji, MN (79.1% good, AQI 36).
Air Quality Summary
Median AQI
36
Good
Good Days
76.6%
262 of 342 days
Max AQI
168
Unhealthy
Health Grade
Good
90th pct: 61
AQI Day Breakdown (2025)
Distribution of 342 monitored days across EPA AQI categories.
Good
262
77%
Moderate
71
21%
USG
5
1%
Unhealthy
4
1%
Very Unhealthy
0
0%
Hazardous
0
0%
Health Impact Assessment
The Wausau, WI metro area's air quality is rated Good based on 76.6% good air days. There were 4 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 168. Sensitive groups should monitor real-time conditions at AirNow.gov.
How does the Wausau, WI metro compare?
How Wausau, WI compares
5-Year Air Quality Trend
Air quality is worsening in the Wausau, WI metro. Highest Good-day share: 2020 (97.0%, 193 of 199 monitored days).
| Year | Good | Moderate | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|
| 2020 | 193 | 6 | 0 | 31 | 74 |
| 2021 | 191 | 9 | 0 | 36 | 87 |
| 2022 | 197 | 8 | 0 | 35 | 64 |
| 2023 | 168 | 39 | 1 | 41 | 166 |
| 2024 | 311 | 54 | 1 | 37 | 151 |
| 2025 | 262 | 71 | 4 | 36 | 168 |
Metros with a similar median AQI
CBSA peers nationwide whose annual median AQI sits near Wausau, WI (36).
Atlantic City-Hammonton, NJ
Median AQI 36 · 82.2% Good-day share
Barnstable Town, MA
Median AQI 36 · 93.7% Good-day share
Bemidji, MN
Median AQI 36 · 79.1% Good-day share
Claremont-Lebanon, NH-VT
Median AQI 36 · 83.6% Good-day share
Crestview-Fort Walton Beach-Destin, FL
Median AQI 36 · 93.9% Good-day share
East Stroudsburg, PA
Median AQI 36 · 88.3% Good-day share
Metros with similar unhealthy-day exposure
A second relationship type: metros whose unhealthy-or-worse day count is closest to Wausau, WI's 4 (independent of median AQI).
Bakersfield, CA
4 unhealthy-or-worse days · median AQI 70
Bishop, CA
4 unhealthy-or-worse days · median AQI 55
Bismarck, ND
4 unhealthy-or-worse days · median AQI 40
Dickinson, ND
4 unhealthy-or-worse days · median AQI 38
New York-Newark-Jersey City, NY-NJ-PA
4 unhealthy-or-worse days · median AQI 53
St. Louis, MO-IL
4 unhealthy-or-worse days · median AQI 56
More Air Quality Data
Explore EPA air quality rankings and guides across U.S. metros and counties.
Cleanest Metro Areas
U.S. metros ranked by their share of Good air-quality days.
Worst Air Quality
Counties and metros with the most unhealthy air days.
All Metro Areas
Annual AQI by CBSA for every monitored U.S. metro area.
Best and Worst City Air
What drives urban air quality and how metro areas compare.
Air Quality Guides
Frequently Asked Questions
What is the air quality in the Wausau, WI metro area? ▼
How many unhealthy air days does Wausau, WI have? ▼
Is air quality in Wausau, WI getting better or worse? ▼
What does AQI 36 mean for health? ▼
What is the 90th percentile AQI for Wausau, WI? ▼
How does Wausau, WI compare to other metro areas? ▼
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset, 2020–2025. 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 files (metro-level) · 2020–2025
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Every figure on PlainAirData is rendered directly from EPA AQS air-quality monitoring data, no number is typed in by an editor. This page draws directly on EPA AQS air-quality monitoring data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.