Dayton Air Quality in 2019
In 2019, Dayton's air quality (Dayton, OH area) had a median daily AQI of 54 (Moderate) across 365 monitored days. 0 days (0.0%) reached Unhealthy for Sensitive Groups or worse, 145 were Good, and the year's peak AQI was 95 (Moderate). Fine particulate matter (PM2.5) set the daily AQI on 251 of those days. The cleanest month of 2019 was October (median AQI 47, 0 days above 100) and the worst was July (median 61, 0 days above 100, peak 87).
- Good: 39.7%
- Moderate: 60.3%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
Improve Indoor Air Quality
Even with good outdoor air in Dayton, indoor PM2.5, dust and allergens build up. A True-HEPA purifier keeps a bedroom or office consistently clean.
Recommended: Levoit Core 400S — True HEPA · CADR ~141 CFM · rooms up to 219 sq ft
As an Amazon Associate, we earn from qualifying purchases.
How was Dayton's air quality in 2019?
Moderate on a typical day: median AQI 54, with 0 days above AQI 100 out of 365 monitored — the 1st cleanest of 7 years on record for the area.
- ✓Peak AQI in 2019: 95 (Moderate).
- ✓Fine particulate matter (PM2.5) was the main pollutant on 251 days.
- ✓Cleanest month: October; worst: July.
Frequently asked questions
What was the average AQI in Dayton in 2019?▾
EPA's Air Quality System puts Dayton's (Dayton, OH) median daily AQI for 2019 at 54, which is Moderate. 0 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 95.
Which month had the worst air quality in Dayton in 2019?▾
The cleanest month of 2019 was October (median AQI 47, 0 days above 100) and the worst was July (median 61, 0 days above 100, peak 87).
Was 2019 a good or bad year for Dayton's air?▾
Among the 7 years EPA has published for the area (2019–2025), 2019 ranks 1st cleanest by days above AQI 100 — the best year on record here. 2019's median of 54 is above the area's typical annual median of 51.
Dayton month by month in 2019
Dayton air quality month by month, 2019 (Dayton, OH, EPA AQS daily AQI)
| Month | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| January | 31 | 55 | 0 | 80 | PM2.5 |
| February | 28 | 56 | 0 | 95 | PM2.5 |
| March | 31 | 52 | 0 | 72 | PM2.5 |
| April | 30 | 48 | 0 | 69 | O3 |
| May | 31 | 54 | 0 | 74 | O3 |
| June | 30 | 50 | 0 | 90 | O3 |
| Julyworst | 31 | 61 | 0 | 87 | PM2.5 |
| August | 31 | 54 | 0 | 93 | O3 |
| September | 30 | 54 | 0 | 87 | O3 |
| Octobercleanest | 31 | 47 | 0 | 69 | PM2.5 |
| November | 30 | 55 | 0 | 87 | PM2.5 |
| December | 31 | 59 | 0 | 84 | PM2.5 |
How 2019 compares
Among the 7 years EPA has published for the area (2019–2025), 2019 ranks 1st cleanest by days above AQI 100 — the best year on record here.
2019's median of 54 is above the area's typical annual median of 51.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Dayton
The latest EPA AirNow observation puts Dayton's AQI at 24 (PM2.5). The figures above are multi-year annual 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.