Metro area air quality · 2025
Dayton, OH
Median AQI 47 (Good). 57.0% of monitored days rated Good across this metro's EPA monitoring network.
- 47
- Median AQI
- 57.0%
- Good-air days
- 0
- Unhealthy days
- 21%
- Cleaner than US metros
Dayton, OH posted a 2025 median AQI of 47 (Good) with 57.0% Good days
According to the U.S. EPA Air Quality System, the Dayton, OH CBSA recorded a median AQI of 47 across 365 monitored days in 2025, with 57.0% rated Good and 0 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 Dayton, OH CBSA's 57.0% Good-day share places it cleaner than 21% of US metros in 2025.
- Closest median-AQI peer
- Charleston-North Charleston, SC (60.3% Good, median AQI 47) is the closest nationwide median-AQI peer to Dayton, OH.
- 2020–2025 Good-day shift
- Dayton, OH's Good-day share moved +11.2 points from 2020 to 2025 (median AQI -5).
- Median AQI
- Median AQI: 47
Aggregated from EPA Air Quality System (2025), 365 monitored days. EPA AQS →
The verdict
Dayton, OH lands in the lower Good-day tercile (57.0% Good), a thinner clean-air share than most CBSA peers here. On the EPA scale the metro runs good, among the more polluted US metros, with a median AQI of 47 and 57.0% of 365 monitored days in the Good band.
- 47
- median AQI · Good
- 57.0%
- days rated Good
- 21%
- cleaner than US metros
- 129
- worst single reading
No day crossed into the Unhealthy tier across the metro's monitors in 2025.
Annual release change
What changed in the 2025 EPA annual release
- Dayton, OH metro's Good-day share fell from 60.2% to 57.6% between the 2024 and 2025 EPA annual releases, a change of -2.6 percentage points.
- Dayton, OH metro's peak single-day AQI fell from 147 to 129 between the 2024 and 2025 EPA annual releases, a change of -18 points.
Dayton, OH lands in the lower Good-day tercile (57.0% Good), a thinner clean-air share than most CBSA peers here. Signature read: 57.0% 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 47 over 365 measured days in 2025 (Good / Moderate). The monitored-day split lands at 208 Good (57%), 153 Moderate (42%), and 4 Unhealthy-for-Sensitive-Groups (1%). The 90th-percentile AQI finished at 69; the highest single-day reading hit 129 (USG).
Across 2020–2025, Good-day share shifted +11.2 points and median AQI moved -5 (improving). No Unhealthy-tier days appear in this annual dataset. Metros with comparable AQI profiles include Charleston-North Charleston, SC (60.3% good, AQI 47); Columbia, SC (58.1% good, AQI 47); Corsicana, TX (59.2% good, AQI 47).
Air Quality Summary
Median AQI
47
Good
Good Days
57.0%
208 of 365 days
Max AQI
129
USG
Health Grade
Moderate
90th pct: 69
AQI Day Breakdown (2025)
Distribution of 365 monitored days across EPA AQI categories.
Good
208
57%
Moderate
153
42%
USG
4
1%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Health Impact Assessment
The Dayton, OH metro area's air quality is rated Moderate based on 57.0% 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 Dayton, OH metro compare?
How Dayton, OH compares
5-Year Air Quality Trend
Air quality is improving in the Dayton, OH metro. Highest Good-day share: 2024 (60.2%, 218 of 362 monitored days).
| Year | Good | Moderate | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|
| 2020 | 168 | 194 | 0 | 52 | 112 |
| 2021 | 156 | 208 | 0 | 53 | 101 |
| 2022 | 196 | 166 | 0 | 49 | 136 |
| 2023 | 178 | 174 | 2 | 51 | 204 |
| 2024 | 218 | 144 | 0 | 47 | 147 |
| 2025 | 208 | 153 | 0 | 47 | 129 |
Metros with a similar median AQI
CBSA peers nationwide whose annual median AQI sits near Dayton, OH (47).
Charleston-North Charleston, SC
Median AQI 47 · 60.3% Good-day share
Columbia, SC
Median AQI 47 · 58.1% Good-day share
Corsicana, TX
Median AQI 47 · 59.2% Good-day share
Evansville, IN-KY
Median AQI 47 · 57.5% Good-day share
Farmington, NM
Median AQI 47 · 68.0% Good-day share
Glenwood Springs, CO
Median AQI 47 · 66.8% Good-day share
Metros with similar unhealthy-day exposure
A second relationship type: metros whose unhealthy-or-worse day count is closest to Dayton, OH's 0 (independent of median AQI).
Aberdeen, SD
0 unhealthy-or-worse days · median AQI 27
Aberdeen, WA
0 unhealthy-or-worse days · median AQI 22
Adrian, MI
0 unhealthy-or-worse days · median AQI 41
Akron, OH
0 unhealthy-or-worse days · median AQI 45
Albany, GA
0 unhealthy-or-worse days · median AQI 46
Albany, OR
0 unhealthy-or-worse days · median AQI 27
Frequently Asked Questions
How many unhealthy air days does Dayton, OH have? ▼
What is the air quality in the Dayton, OH metro area? ▼
Is air quality in Dayton, OH getting better or worse? ▼
What does AQI 47 mean for health? ▼
How does Dayton, OH compare to other metro areas? ▼
What is the 90th percentile AQI for Dayton, OH? ▼
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset for Dayton, OH, 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, Dayton, OH · 2020–2025