Metro area air quality · 2025
Baraboo, WI
Median AQI 35 (Good). 75.6% of monitored days rated Good across this metro's EPA monitoring network.
- 35
- Median AQI
- 75.6%
- Good-air days
- 1
- Unhealthy days
- 57%
- Cleaner than US metros
Baraboo, WI posted a 2025 median AQI of 35 (Good) with 75.6% Good days
According to the U.S. EPA Air Quality System, the Baraboo, WI CBSA recorded a median AQI of 35 across 365 monitored days in 2025, with 75.6% rated Good and 1 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 Baraboo, WI CBSA's 75.6% Good-day share places it cleaner than 57% of US metros in 2025.
- Closest median-AQI peer
- Effingham, IL (95.5% Good, median AQI 35) is the closest nationwide median-AQI peer to Baraboo, WI.
- 2020–2025 Good-day shift
- Baraboo, WI's Good-day share moved +4.3 points from 2020 to 2025 (median AQI -6).
- Median AQI
- Median AQI: 35
Aggregated from EPA Air Quality System (2025), 365 monitored days. EPA AQS →
The verdict
Baraboo, WI's median AQI 35 is in the lower (cleaner) CBSA tercile on this site. On the EPA scale the metro runs good, cleaner than the median US metro, with a median AQI of 35 and 75.6% of 365 monitored days in the Good band.
- 35
- median AQI · Good
- 75.6%
- days rated Good
- 57%
- cleaner than US metros
- 167
- worst single reading
1 day reached Unhealthy or worse across the metro's monitors in 2025.
Annual release change
What changed in the 2025 EPA annual release
- Baraboo, WI metro's peak single-day AQI rose from 77 to 167 between the 2024 and 2025 EPA annual releases, a change of +90 points.
- Baraboo, WI metro's Good-day share fell from 85.2% to 76.7% between the 2024 and 2025 EPA annual releases, a change of -8.6 percentage points.
- Baraboo, WI metro's Unhealthy-category days rose from 0 to 1 between the 2024 and 2025 EPA annual releases, a change of +1 days.
Baraboo, WI's median AQI 35 is in the lower (cleaner) CBSA tercile on this site. Signature read: median AQI 35 (low tercile vs CBSA corpus). Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 35 over 365 measured days in 2025 (Good / Good). The monitored-day split lands at 276 Good (76%), 83 Moderate (23%), and 5 Unhealthy-for-Sensitive-Groups (1%). The 90th-percentile AQI finished at 58; the highest single-day reading hit 167 (Unhealthy).
Across 2020–2025, Good-day share shifted +4.3 points and median AQI moved -6 (improving). The annual record contains 1 day at Unhealthy or worse. Metros with comparable AQI profiles include Effingham, IL (95.5% good, AQI 35); Ithaca, NY (93.2% good, AQI 35); Kinston, NC (97.5% good, AQI 35).
Air Quality Summary
Median AQI
35
Good
Good Days
75.6%
276 of 365 days
Max AQI
167
Unhealthy
Health Grade
Good
90th pct: 58
AQI Day Breakdown (2025)
Distribution of 365 monitored days across EPA AQI categories.
Good
276
76%
Moderate
83
23%
USG
5
1%
Unhealthy
1
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Health Impact Assessment
The Baraboo, WI metro area's air quality is rated Good based on 75.6% good air days. There were 1 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 167. Sensitive groups should monitor real-time conditions at AirNow.gov.
How does the Baraboo, WI metro compare?
How Baraboo, WI compares
5-Year Air Quality Trend
Air quality is improving in the Baraboo, WI metro. Highest Good-day share: 2024 (85.2%, 312 of 366 monitored days).
| Year | Good | Moderate | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|
| 2020 | 264 | 101 | 0 | 41 | 112 |
| 2021 | 236 | 129 | 0 | 44 | 96 |
| 2022 | 265 | 95 | 0 | 41 | 79 |
| 2023 | 218 | 123 | 4 | 44 | 271 |
| 2024 | 312 | 54 | 0 | 37 | 77 |
| 2025 | 276 | 83 | 1 | 35 | 167 |
Metros with a similar median AQI
CBSA peers nationwide whose annual median AQI sits near Baraboo, WI (35).
Effingham, IL
Median AQI 35 · 95.5% Good-day share
Ithaca, NY
Median AQI 35 · 93.2% Good-day share
Kinston, NC
Median AQI 35 · 97.5% Good-day share
Meridian, MS
Median AQI 35 · 94.6% Good-day share
Morehead City, NC
Median AQI 35 · 96.2% Good-day share
Salem, OR
Median AQI 35 · 80.0% Good-day share
Metros with similar unhealthy-day exposure
A second relationship type: metros whose unhealthy-or-worse day count is closest to Baraboo, WI's 1 (independent of median AQI).
Ann Arbor, MI
1 unhealthy-or-worse days · median AQI 41
Bangor, ME
1 unhealthy-or-worse days · median AQI 33
Bartlesville, OK
1 unhealthy-or-worse days · median AQI 44
Beaumont-Port Arthur, TX
1 unhealthy-or-worse days · median AQI 52
Beaver Dam, WI
1 unhealthy-or-worse days · median AQI 40
Bellingham, WA
1 unhealthy-or-worse days · median AQI 31
Frequently Asked Questions
What does AQI 35 mean for health? ▼
How many unhealthy air days does Baraboo, WI have? ▼
What is the air quality in the Baraboo, WI metro area? ▼
Is air quality in Baraboo, WI getting better or worse? ▼
How does Baraboo, WI compare to other metro areas? ▼
What is the 90th percentile AQI for Baraboo, WI? ▼
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset for Baraboo, WI, 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, Baraboo, WI · 2020–2025