Dayton Air Quality in Summer

Across 2019–2025, Dayton's summer (June–August) air quality had a median AQI of 55 (Moderate) over 644 monitored days in the Dayton, OH area. 4.2% of summer days (27 of 644) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 54.5% of days. The cleanest summer on record here was 2019 (median AQI 55, 0 days above 100) and the worst was 2023 (median 65, 13 days above 100, peak AQI 204).

55
Median AQI
Moderate
4.2%
Days above AQI 100
27 of 644 days
84
90th percentile AQI
worst 1 day in 10
204
Peak AQI
Very Unhealthy
PM2.5
Main pollutant
54.5% of days
36.5%
Good days
235 of 644
  • Good: 36.5%
  • Moderate: 59.3%
  • Unhealthy for Sensitive Groups: 3.7%
  • Unhealthy or worse: 0.5%

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QUICK ANSWER

How is the air in Dayton in summer?

Moderate on a typical day: median AQI 55 across 2019–2025, with 4.2% of summer days above AQI 100. Fine particulate matter (PM2.5) is the main driver.

  • 36.5% of summer days were Good (AQI 0–50), 59.3% Moderate (51–100).
  • 27 days of 644 reached AQI 101+; the summer peak was 204.
  • Cleanest month: August; worst month: June.

Frequently asked questions

What is the air quality like in Dayton in summer?

Across 2019–2025, the median daily AQI in Dayton in summer was 55 (Moderate). 36.5% of days were Good, 59.3% Moderate, and 4.2% reached Unhealthy for Sensitive Groups or worse, based on 644 monitored days in EPA's Air Quality System.

Is summer a good time for outdoor exercise in Dayton?

A typical summer day in Dayton is Moderate (median AQI 55): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 24 of summer days (4.2%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.

Which pollutant causes Dayton's summer air quality problems?

Fine particulate matter (PM2.5) set the daily AQI on 54.5% of summer days in Dayton. The highest summer AQI recorded in 2019–2025 was 204 (Very Unhealthy), in 2023.

Dayton summer air quality, year by year

Dayton summer air quality by year (Dayton, OH, EPA AQS daily AQI)

YearDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
2019cleanest9255093PM2.5
202092554112O3
202192571101PM2.5
202292523136PM2.5
2023worst926513204PM2.5
202492544147O3
202592542129PM2.5

What summer air means in Dayton

A typical summer day in Dayton is Moderate (median AQI 55): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 24 of summer days (4.2%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.

Summer's median AQI of 55 is above Dayton's whole-year median of 51, making it one of the area's dirtier periods. Nationally, the median Summer AQI across every EPA metro area (308,645 metro-days, 2019–2025) is 46, so Dayton runs above the national Summer norm; 4.2% of its Summer days topped AQI 100 versus 3.6% nationally (about the same).

Within the season, August is the cleanest month (median AQI 52, 0.9% of days above 100) and June the worst (median 58, 8.5% above 100).

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 season 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.