Cincinnati weather in September
September in Cincinnati: warm, a little rain, with clean air — one of the best months to visit.
#1 of 12 months in Cincinnati · #67 of 897 destinations to visit in September · comfort 93/100 (tier S)
Updated June 2026 · climate normals from ERA5 reanalysis
Traveller notes on Cincinnati in September
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Cincinnati climate normals — September
| Daytime high | 26°C / 79°F | 🌤 warm |
|---|---|---|
| Nighttime low | 16°C / 61°F | |
| Rainfall | 44 mm / 1.7 in | 🌦 some rain |
| Rainy days | 6 days | |
| Humidity | 68% | 💧 humid |
| Dew point | 14°C / 57°F | |
| Sunshine | 10.1 h/day | |
| Daylight | 12.4 h | |
| Wind | 14 km/h / 8 mph | |
| Air quality (US AQI) | 46 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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Cincinnati in September — FAQ
- Is September a good time to visit Cincinnati?
- September in Cincinnati: warm, a little rain, with clean air — one of the best months to visit. It ranks #1 of 12 months for Cincinnati on SeasonMap's comfort score (93/100).
- What is the weather like in Cincinnati in September?
- In September, Cincinnati averages a daily high of 26.1°C and a low of 16.3°C, with about 44.3 mm of rain over roughly 6 rainy days.
- What is the air quality in Cincinnati in September?
- Cincinnati has a mean US Air Quality Index of about 46 in September.