Metro area air quality · 2025

Cincinnati, OH-KY-IN

Median AQI 56 (Moderate). 26.0% of monitored days rated Good across this metro's EPA monitoring network.

56
Median AQI
26.0%
Good-air days
2
Unhealthy days
2%
Cleaner than US metros

Cincinnati, OH-KY-IN posted a 2025 median AQI of 56 (Moderate) with 26.0% Good days

According to the U.S. EPA Air Quality System, the Cincinnati, OH-KY-IN CBSA recorded a median AQI of 56 across 365 monitored days in 2025, with 26.0% rated Good and 2 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 Cincinnati, OH-KY-IN CBSA's 26.0% Good-day share places it cleaner than 2% of US metros in 2025.
Closest median-AQI peer
Chicago-Naperville-Elgin, IL-IN-WI (29.9% Good, median AQI 56) is the closest nationwide median-AQI peer to Cincinnati, OH-KY-IN.
2020–2025 Good-day shift
Cincinnati, OH-KY-IN's Good-day share moved -0.3 points from 2020 to 2025 (median AQI +1).
Median AQI
Median AQI: 56

Aggregated from EPA Air Quality System (2025), 365 monitored days. EPA AQS →

The verdict

Cincinnati, OH-KY-IN lands in the lower Good-day tercile (26.0% Good), a thinner clean-air share than most CBSA peers here. On the EPA scale the metro runs moderate, among the more polluted US metros, with a median AQI of 56 and 26.0% of 365 monitored days in the Good band.

56
median AQI · Moderate
26.0%
days rated Good
2%
cleaner than US metros
154
worst single reading

2 days reached Unhealthy or worse across the metro's monitors in 2025.

Annual release change

What changed in the 2025 EPA annual release

2024 → 2025
  • Cincinnati, OH-KY-IN metro's Good-day share fell from 37.2% to 27.0% between the 2024 and 2025 EPA annual releases, a change of -10.2 percentage points.
  • Cincinnati, OH-KY-IN metro's Unhealthy-category days rose from 0 to 2 between the 2024 and 2025 EPA annual releases, a change of +2 days.

Compared against 352 monitored days in 2024 and 352 in 2025. These are arithmetic differences between two stored EPA annual summaries, not a cause claim or a live advisory.

National release changes Two-year CSV

Cincinnati, OH-KY-IN lands in the lower Good-day tercile (26.0% Good), a thinner clean-air share than most CBSA peers here. Signature read: 26.0% Good-day share (low tercile vs CBSA corpus). Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 56 over 365 measured days in 2025 (Moderate / Poor). The monitored-day split lands at 95 Good (26%), 255 Moderate (70%), and 13 Unhealthy-for-Sensitive-Groups (4%). The 90th-percentile AQI finished at 78; the highest single-day reading hit 154 (Unhealthy).

Across 2020–2025, Good-day share shifted -0.3 points and median AQI moved +1 (stable). The annual record contains 2 days at Unhealthy or worse. Metros with comparable AQI profiles include Chicago-Naperville-Elgin, IL-IN-WI (29.9% good, AQI 56); St. Louis, MO-IL (31.2% good, AQI 56); Bishop, CA (37.3% good, AQI 55).

Health effects of air pollution →

Air Quality Summary

Median AQI

56

Moderate

Good Days

26.0%

95 of 365 days

Max AQI

154

Unhealthy

Health Grade

Poor

90th pct: 78

AQI Day Breakdown (2025)

Distribution of 365 monitored days across EPA AQI categories.

Good

95

26%

Moderate

255

70%

USG

13

4%

Unhealthy

2

1%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Poor

The Cincinnati, OH-KY-IN metro area's air quality is rated Poor based on 26.0% good air days. There were 2 unhealthy days in 2025 when outdoor activity should be limited.

Air quality is acceptable most days, but 13 days reached "Unhealthy for Sensitive Groups" and peak AQI reached 154. Sensitive groups should monitor real-time conditions at AirNow.gov.

How does the Cincinnati, OH-KY-IN metro compare?

How Cincinnati, OH-KY-IN compares

Good-day share worse than typical
Cincinnati, OH-KY-IN 26.0%
Chicago-Naperville-Elgin, IL-IN-WI 29.9%
Typical US metro 70.6%
Median AQI worse than typical
Cincinnati, OH-KY-IN 56
Chicago-Naperville-Elgin, IL-IN-WI 56
Typical US metro 41
Unhealthy days / yr worse than typical
Cincinnati, OH-KY-IN 2
Chicago-Naperville-Elgin, IL-IN-WI 6
Typical US metro 1

5-Year Air Quality Trend

Air quality is stable in the Cincinnati, OH-KY-IN metro. Highest Good-day share: 2024 (37.2%, 131 of 352 monitored days).

Year Good Moderate Unhealthy Median AQI
2020 98 261 0 55
2021 92 265 0 57
2022 104 255 1 56
2023 92 249 5 57
2024 131 221 0 54
2025 95 255 2 56

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near Cincinnati, OH-KY-IN (56).

Metros with similar unhealthy-day exposure

A second relationship type: metros whose unhealthy-or-worse day count is closest to Cincinnati, OH-KY-IN's 2 (independent of median AQI).

Frequently Asked Questions

How many unhealthy air days does Cincinnati, OH-KY-IN have?
In 2025, the Cincinnati, OH-KY-IN metro area recorded 2 unhealthy air days (2 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 154.
What is the air quality in the Cincinnati, OH-KY-IN metro area?
The Cincinnati, OH-KY-IN metro area has a median Air Quality Index (AQI) of 56, rated "Moderate." 26.0% of monitored days (95 out of 365) had good air quality in 2025.
Is air quality in Cincinnati, OH-KY-IN getting better or worse?
Air quality in the Cincinnati, OH-KY-IN metro is stable across floor-qualifying years (2020-2025); years with fewer than 100 monitored days are excluded from that direction. Highest qualifying Good-day share: 2024 at 37.2% (131 of 352 days). Lowest qualifying Good-day share: 2021 at 25.8% (92 of 357 days).
What does AQI 56 mean for health?
An AQI of 56 is "Moderate", air quality is acceptable, but some pollutants may pose a moderate health concern for a small number of sensitive individuals.
How does Cincinnati, OH-KY-IN compare to other metro areas?
The Cincinnati, OH-KY-IN metro has 26.0% good air days. Similar metros: Chicago-Naperville-Elgin, IL-IN-WI (29.9% good), St. Louis, MO-IL (31.2% good), Bishop, CA (37.3% good).
What is the 90th percentile AQI for Cincinnati, OH-KY-IN?
The 90th percentile AQI for the Cincinnati, OH-KY-IN metro area is 78, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 154 (Unhealthy).

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset for Cincinnati, OH-KY-IN, 2025. See our methodology for how AQI, median, and coverage figures are computed.

Source: U.S. EPA Air Quality System (AQS) Annual AQI by CBSA summary, Cincinnati, OH-KY-IN · 2020–2025