Metro area air quality · 2025
Iowa City, IA
Median AQI 36 (Good). 71.0% of monitored days rated Good across this metro's EPA monitoring network.
- 36
- Median AQI
- 71.0%
- Good-air days
- 1
- Unhealthy days
- 46%
- Cleaner than US metros
Aggregated from EPA Air Quality System (2025), 304 monitored days. EPA AQS →
The verdict
The Iowa City, IA metro runs good on the EPA scale, more polluted than the median US metro, a median AQI of 36 with 71.0% of 304 monitored days in the Good band.
- 36
- median AQI · Good
- 71.0%
- days rated Good
- 46%
- cleaner than US metros
- 159
- worst single reading
1 day reached Unhealthy or worse across the metro's monitors in 2025.
Insights: Iowa City, IA metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 36 over 304 measured days in 2025, which corresponds to a Good band and a Moderate metro-wide health grade. The monitored-day split lands at 216 Good days (71%), 84 Moderate (28%), and 3 Unhealthy-for-Sensitive-Groups (1%). The 90th-percentile AQI finished at 62 while the highest single-day reading hit 159 (Unhealthy). Metro residents averaged roughly 21.3 clean-air days per 30-day window across the reporting year.
Across the 2020–2025 trend window, good days shifted by +9 and the median AQI moved -11 points, which classifies the multi-year trajectory as improving. The metro recorded 1 unhealthy-or-worse days combined, on those days the EPA recommends that sensitive groups limit prolonged outdoor exertion, and many schools and athletic programs adjust outdoor activity accordingly. 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
71.0%
216 of 304 days
Max AQI
159
Unhealthy
Health Grade
Moderate
90th pct: 62
AQI Day Breakdown (2025)
Distribution of 304 monitored days across EPA AQI categories.
Good
216
71%
Moderate
84
28%
USG
3
1%
Unhealthy
1
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Health Impact Assessment
The Iowa City, IA metro area's air quality is rated Moderate based on 71.0% good air days. There were 1 unhealthy days in 2025 when outdoor activity should be limited.
Air quality is acceptable most days, but 3 days reached "Unhealthy for Sensitive Groups" and peak AQI reached 159. Sensitive groups should monitor real-time conditions at AirNow.gov.
How does the Iowa City, IA metro compare?
How Iowa City, IA compares
5-Year Air Quality Trend
Air quality is improving in the Iowa City, IA metro. Best year: 2024 (259 good days).
| Year | Good | Moderate | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|
| 2020 | 207 | 154 | 0 | 47 | 105 |
| 2021 | 172 | 190 | 0 | 52 | 121 |
| 2022 | 223 | 141 | 0 | 44 | 108 |
| 2023 | 143 | 216 | 3 | 53 | 210 |
| 2024 | 259 | 107 | 0 | 39 | 83 |
| 2025 | 216 | 84 | 1 | 36 | 159 |
Metros with Similar Air Quality
Metro areas across the US with a similar median AQI to Iowa City, IA.
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 Iowa City, IA metro area? ▼
How many unhealthy air days does Iowa City, IA have? ▼
Is air quality in Iowa City, IA getting better or worse? ▼
What does AQI 36 mean for health? ▼
What is the 90th percentile AQI for Iowa City, IA? ▼
How does Iowa City, IA 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
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.