Cincinnati Air Quality in May
Across 2019–2025, Cincinnati's May air quality had a median AQI of 54 (Moderate) over 217 monitored days in the Cincinnati, OH-KY-IN area. 0.5% of May days (1 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 58.5% of days. The cleanest May on record here was 2020 (median AQI 52, 0 days above 100) and the worst was 2023 (median 59, 1 day above 100, peak AQI 112).
- Good: 30.0%
- Moderate: 69.6%
- Unhealthy for Sensitive Groups: 0.5%
- 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 Mighty — True HEPA + carbon · CADR ~246 CFM · rooms up to 361 sq ft
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How is the air in Cincinnati in May?
Moderate on a typical day: median AQI 54 across 2019–2025, with 0.5% of May days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓30.0% of May days were Good (AQI 0–50), 69.6% Moderate (51–100).
- ✓1 day of 217 reached AQI 101+; the May peak was 112.
- ✓Best May: 2020; worst May: 2023.
Frequently asked questions
What is the air quality like in Cincinnati in May?▾
Across 2019–2025, the median daily AQI in Cincinnati in May was 54 (Moderate). 30.0% of days were Good, 69.6% Moderate, and 0.5% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is May a good time for outdoor exercise in Cincinnati?▾
A typical May 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 May 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 May air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 58.5% of May days in Cincinnati. The highest May AQI recorded in 2019–2025 was 112 (Unhealthy for Sensitive Groups), in 2023.
Cincinnati May air quality, year by year
Cincinnati May air quality by year (Cincinnati, OH-KY-IN, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 60 | 0 | 100 | PM2.5 |
| 2020cleanest | 31 | 52 | 0 | 74 | PM2.5 |
| 2021 | 31 | 55 | 0 | 97 | PM2.5 |
| 2022 | 31 | 55 | 0 | 77 | PM2.5 |
| 2023worst | 31 | 59 | 1 | 112 | O3 |
| 2024 | 31 | 54 | 0 | 93 | PM2.5 |
| 2025 | 31 | 52 | 0 | 84 | PM2.5 |
What May air means in Cincinnati
A typical May 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 May days reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
May'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 May AQI across every EPA metro area (104,064 metro-days, 2019–2025) is 44, so Cincinnati runs above the national May norm; 0.5% of its May days topped AQI 100 versus 1.3% nationally (about the same).
May is part of Cincinnati's spring season (March, April, May); the spring 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.