Metro area air quality · 2025
Bloomington, IL
Median AQI 44 (Good). 66.0% of monitored days rated Good across this metro's EPA monitoring network.
- 44
- Median AQI
- 66.0%
- Good-air days
- 1
- Unhealthy days
- 36%
- Cleaner than US metros
Bloomington, IL posted a 2025 median AQI of 44 (Good) with 66.0% Good days
According to the U.S. EPA Air Quality System, the Bloomington, IL CBSA recorded a median AQI of 44 across 365 monitored days in 2025, with 66.0% 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 Bloomington, IL CBSA's 66.0% Good-day share places it cleaner than 36% of US metros in 2025.
- Closest median-AQI peer
- Bartlesville, OK (68.0% Good, median AQI 44) is the closest nationwide median-AQI peer to Bloomington, IL.
- 2020–2025 Good-day shift
- Bloomington, IL's Good-day share moved +9.2 points from 2020 to 2025 (median AQI -4).
- Median AQI
- Median AQI: 44
Aggregated from EPA Air Quality System (2025), 365 monitored days. EPA AQS →
The verdict
Bloomington, IL's peak reading 154 is in the upper max-AQI tercile among CBSA metros here. On the EPA scale the metro runs good, more polluted than the median US metro, with a median AQI of 44 and 66.0% of 365 monitored days in the Good band.
- 44
- median AQI · Good
- 66.0%
- days rated Good
- 36%
- cleaner than US metros
- 154
- 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
- Bloomington, IL metro's peak single-day AQI rose from 112 to 154 between the 2024 and 2025 EPA annual releases, a change of +42 points.
- Bloomington, IL metro's Good-day share fell from 69.6% to 66.6% between the 2024 and 2025 EPA annual releases, a change of -3.0 percentage points.
- Bloomington, IL metro's Unhealthy-category days rose from 0 to 1 between the 2024 and 2025 EPA annual releases, a change of +1 days.
Bloomington, IL's peak reading 154 is in the upper max-AQI tercile among CBSA metros here. Signature read: peak AQI 154 (high tercile vs CBSA corpus). Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 44 over 365 measured days in 2025 (Good / Moderate). The monitored-day split lands at 241 Good (66%), 120 Moderate (33%), and 3 Unhealthy-for-Sensitive-Groups (1%). The 90th-percentile AQI finished at 67; the highest single-day reading hit 154 (Unhealthy).
Across 2020–2025, Good-day share shifted +9.2 points and median AQI moved -4 (improving). The annual record contains 1 day at Unhealthy or worse. Metros with comparable AQI profiles include Bartlesville, OK (68.0% good, AQI 44); Berlin, NH-VT (81.5% good, AQI 44); Boston-Cambridge-Newton, MA-NH (71.0% good, AQI 44).
Air Quality Summary
Median AQI
44
Good
Good Days
66.0%
241 of 365 days
Max AQI
154
Unhealthy
Health Grade
Moderate
90th pct: 67
AQI Day Breakdown (2025)
Distribution of 365 monitored days across EPA AQI categories.
Good
241
66%
Moderate
120
33%
USG
3
1%
Unhealthy
1
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Health Impact Assessment
The Bloomington, IL metro area's air quality is rated Moderate based on 66.0% 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 154. Sensitive groups should monitor real-time conditions at AirNow.gov.
How does the Bloomington, IL metro compare?
How Bloomington, IL compares
5-Year Air Quality Trend
Air quality is improving in the Bloomington, IL metro. Highest Good-day share: 2024 (69.6%, 254 of 365 monitored days).
| Year | Good | Moderate | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|
| 2020 | 207 | 154 | 0 | 48 | 136 |
| 2021 | 191 | 173 | 0 | 48 | 107 |
| 2022 | 207 | 156 | 0 | 47 | 129 |
| 2023 | 184 | 168 | 2 | 50 | 289 |
| 2024 | 254 | 111 | 0 | 44 | 112 |
| 2025 | 241 | 120 | 1 | 44 | 154 |
Metros with a similar median AQI
CBSA peers nationwide whose annual median AQI sits near Bloomington, IL (44).
Bartlesville, OK
Median AQI 44 · 68.0% Good-day share
Berlin, NH-VT
Median AQI 44 · 81.5% Good-day share
Boston-Cambridge-Newton, MA-NH
Median AQI 44 · 71.0% Good-day share
Bridgeport-Stamford-Norwalk, CT
Median AQI 44 · 64.7% Good-day share
Buffalo-Cheektowaga-Niagara Falls, NY
Median AQI 44 · 63.8% Good-day share
Cedar City, UT
Median AQI 44 · 74.7% Good-day share
Metros with similar unhealthy-day exposure
A second relationship type: metros whose unhealthy-or-worse day count is closest to Bloomington, IL'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
Baraboo, WI
1 unhealthy-or-worse days · median AQI 35
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 is the 90th percentile AQI for Bloomington, IL? ▼
How many unhealthy air days does Bloomington, IL have? ▼
What is the air quality in the Bloomington, IL metro area? ▼
Is air quality in Bloomington, IL getting better or worse? ▼
What does AQI 44 mean for health? ▼
How does Bloomington, IL compare to other metro areas? ▼
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset for Bloomington, IL, 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, Bloomington, IL · 2020–2025