Dayton Air Quality in October
Across 2019–2025, Dayton's October air quality had a median AQI of 44 (Good) over 217 monitored days in the Dayton, OH area. 0.0% of October days (0 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 68.2% of days. The cleanest October on record here was 2025 (median AQI 39, 0 days above 100) and the worst was 2021 (median 51, 0 days above 100, peak AQI 63).
- Good: 64.5%
- Moderate: 35.5%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
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How is the air in Dayton in October?
Good on a typical day: median AQI 44 across 2019–2025, with 0.0% of October days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓64.5% of October days were Good (AQI 0–50), 35.5% Moderate (51–100).
- ✓0 days of 217 reached AQI 101+; the October peak was 84.
- ✓Best October: 2025; worst October: 2021.
Frequently asked questions
What is the air quality like in Dayton in October?▾
Across 2019–2025, the median daily AQI in Dayton in October was 44 (Good). 64.5% of days were Good, 35.5% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is October a good time for outdoor exercise in Dayton?▾
A typical October day in Dayton sits in the Good range (median AQI 44), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of October days reached AQI 101+ in 2019–2025.
Which pollutant causes Dayton's October air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 68.2% of October days in Dayton. The highest October AQI recorded in 2019–2025 was 84 (Moderate), in 2021.
Dayton October air quality, year by year
Dayton October air quality by year (Dayton, OH, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 47 | 0 | 69 | PM2.5 |
| 2020 | 31 | 48 | 0 | 66 | PM2.5 |
| 2021worst | 31 | 51 | 0 | 63 | PM2.5 |
| 2022 | 31 | 44 | 0 | 68 | PM2.5 |
| 2023 | 31 | 41 | 0 | 64 | PM2.5 |
| 2024 | 31 | 47 | 0 | 74 | PM2.5 |
| 2025cleanest | 31 | 39 | 0 | 84 | O3 |
What October air means in Dayton
A typical October day in Dayton sits in the Good range (median AQI 44), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of October days reached AQI 101+ in 2019–2025.
October's median AQI of 44 is below Dayton's whole-year median of 51, making it one of the area's cleaner periods. Nationally, the median October AQI across every EPA metro area (102,872 metro-days, 2019–2025) is 38, so Dayton runs above the national October norm; 0.0% of its October days topped AQI 100 versus 1.3% nationally (below average).
October is part of Dayton's fall season (September, October, November); the fall page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Dayton
The latest EPA AirNow observation puts Dayton's AQI at 50 (PM2.5). The figures above are multi-year month statistics, not today's reading.
View current Dayton air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Dayton, OH), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.