Metro area air quality · 2025

Wausau, WI

Median AQI 36 (Good). 80.0% of monitored days rated Good across this metro's EPA monitoring network.

36
Median AQI
80.0%
Good-air days
0
Unhealthy days
64%
Cleaner than US metros

Aggregated from EPA Air Quality System (2025), 180 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 80.0% of 180 monitored days in the Good band.

36
median AQI · Good
80.0%
days rated Good
64%
cleaner than US metros
113
worst single reading

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

Insights: Wausau, WI metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 36 over 180 measured days in 2025, which corresponds to a Good band and a Good metro-wide health grade. The monitored-day split lands at 144 Good days (80%), 34 Moderate (19%), and 2 Unhealthy-for-Sensitive-Groups (1%). The 90th-percentile AQI finished at 59 while the highest single-day reading hit 113 (USG). Metro residents averaged roughly 24.0 clean-air days per 30-day window across the reporting year.

Across the 2020–2025 trend window, good days shifted by -49 and the median AQI moved +5 points, which classifies the multi-year trajectory as worsening. The metro avoided any Unhealthy-tier days entirely, an outcome that typically reflects favorable wind patterns, lower industrial density, or effective regional emission controls. Metros with comparable AQI profiles include Augusta-Waterville, ME (83.5% good, AQI 36); Beatrice, NE (74.0% good, AQI 36); Eureka-Arcata-Fortuna, CA (83.2% good, AQI 36).

Air Quality Summary

Median AQI

36

Good

Good Days

80.0%

144 of 180 days

Max AQI

113

USG

Health Grade

Good

90th pct: 59

AQI Day Breakdown (2025)

Distribution of 180 monitored days across EPA AQI categories.

Good

144

80%

Moderate

34

19%

USG

2

1%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Good

The Wausau, WI metro area's air quality is rated Good based on 80.0% 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 Wausau, WI metro compare?

How Wausau, WI compares

Good-day share better than US avg
Wausau, WI 80.0%
Augusta-Waterville, ME 83.5%
US average 71.3%
Median AQI better than US avg
Wausau, WI 36
Augusta-Waterville, ME 36
US average 41
Unhealthy days / yr better than US avg
Wausau, WI 0
Augusta-Waterville, ME 0
US average 1

5-Year Air Quality Trend

Air quality is worsening in the Wausau, WI metro. Best year: 2024 (311 good days).

Year Good Moderate Unhealthy Median AQI
2020 193 6 0 31
2021 191 9 0 36
2022 197 8 0 35
2023 168 39 1 41
2024 311 54 1 37
2025 144 34 0 36

Metros with Similar Air Quality

Metro areas across the US with a similar median AQI to Wausau, WI.

Augusta-Waterville, ME

AQI 36 · 83.5% good

36

Beatrice, NE

AQI 36 · 74.0% good

36

Eureka-Arcata-Fortuna, CA

AQI 36 · 83.2% good

36

Iowa City, IA

AQI 36 · 71.0% good

36

Kennewick-Richland, WA

AQI 36 · 86.0% good

36

Lincoln, NE

AQI 36 · 77.7% good

36

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? ▼
The Wausau, WI metro area has a median Air Quality Index (AQI) of 36, rated "Good." 80.0% of monitored days (144 out of 180) had good air quality in 2025.
How many unhealthy air days does Wausau, WI have? ▼
In 2025, the Wausau, WI metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 113.
Is air quality in Wausau, WI getting better or worse? ▼
Air quality in the Wausau, WI metro is worsening based on 5-year trends (2020-2025). Best year: 2024 with 311 good days. Worst year: 2025 with 144 good days.
What does AQI 36 mean for health? ▼
An AQI of 36 is "Good", air quality is satisfactory and poses little or no health risk. This is the best category on the EPA's AQI scale.
What is the 90th percentile AQI for Wausau, WI? ▼
The 90th percentile AQI for the Wausau, WI metro area is 59, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 113 (USG).
How does Wausau, WI compare to other metro areas? ▼
The Wausau, WI metro has 80.0% good air days. Similar metros: Augusta-Waterville, ME (83.5% good), Beatrice, NE (74.0% good), Eureka-Arcata-Fortuna, CA (83.2% good).

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

Every figure on PlainAir 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.