Cincinnati Air Quality in October

Across 2019–2025, Cincinnati's October air quality had a median AQI of 54 (Moderate) over 217 monitored days in the Cincinnati, OH-KY-IN 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 88.9% of days. The cleanest October on record here was 2025 (median AQI 52, 0 days above 100) and the worst was 2024 (median 60, 0 days above 100, peak AQI 87).

54
Median AQI
Moderate
0.0%
Days above AQI 100
0 of 217 days
66
90th percentile AQI
worst 1 day in 10
93
Peak AQI
Moderate
PM2.5
Main pollutant
88.9% of days
34.1%
Good days
74 of 217
  • Good: 34.1%
  • Moderate: 65.9%
  • Unhealthy for Sensitive Groups: 0.0%
  • Unhealthy or worse: 0.0%

Extra Protection for Cincinnati Homes

Air quality in Cincinnati is moderate (AQI 65), with fine particles (PM2.5) the main concern. A True-HEPA purifier gives sensitive groups — kids, seniors and anyone with asthma or allergies — cleaner air indoors on days like today.

Recommended: Coway AP-1512HH MightyTrue HEPA + carbon · CADR ~246 CFM · rooms up to 361 sq ft

Check Price on Amazon →

As an Amazon Associate, we earn from qualifying purchases.

QUICK ANSWER

How is the air in Cincinnati in October?

Moderate on a typical day: median AQI 54 across 2019–2025, with 0.0% of October days above AQI 100. Fine particulate matter (PM2.5) is the main driver.

  • 34.1% of October days were Good (AQI 0–50), 65.9% Moderate (51–100).
  • 0 days of 217 reached AQI 101+; the October peak was 93.
  • Best October: 2025; worst October: 2024.

Frequently asked questions

What is the air quality like in Cincinnati in October?

Across 2019–2025, the median daily AQI in Cincinnati in October was 54 (Moderate). 34.1% of days were Good, 65.9% 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 Cincinnati?

A typical October day in Cincinnati is Moderate (median AQI 54): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and fewer than 1% of October days reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.

Which pollutant causes Cincinnati's October air quality problems?

Fine particulate matter (PM2.5) set the daily AQI on 88.9% of October days in Cincinnati. The highest October AQI recorded in 2019–2025 was 93 (Moderate), in 2024.

Cincinnati October air quality, year by year

Cincinnati October air quality by year (Cincinnati, OH-KY-IN, EPA AQS daily AQI)

YearDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
20193157074PM2.5
20203154070PM2.5
20213153068PM2.5
20223154077PM2.5
20233154080PM2.5
2024worst3160087PM2.5
2025cleanest3152093PM2.5

What October air means in Cincinnati

A typical October day in Cincinnati is Moderate (median AQI 54): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and fewer than 1% of October days reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.

October's median AQI of 54 is in line with Cincinnati's whole-year median of 56, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median October AQI across every EPA metro area (102,872 metro-days, 2019–2025) is 38, so Cincinnati 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 Cincinnati's fall season (September, October, November); the fall page pools all three months.

Activity-specific thresholds: running, cycling, kids' sports.

Right now in Cincinnati

The latest EPA AirNow observation puts Cincinnati's AQI at 65 (PM2.5). The figures above are multi-year month statistics, not today's reading.

View current Cincinnati air quality →

Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Cincinnati, OH-KY-IN), 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.