Hamilton weather in September
September in Hamilton: hot, rainy, with clean air — a great time to visit.
#6 of 12 months in Hamilton · #334 of 604 destinations to visit in September · comfort 78/100 (tier B)
Updated June 2026 · climate normals from ERA5 reanalysis
Hamilton climate normals — September
| Daytime high | 27°C / 80°F | 🥵 hot |
|---|---|---|
| Nighttime low | 26°C / 78°F | |
| Feels like (high) | 30°C / 86°F | |
| Rainfall | 116 mm / 4.6 in | 🌧 rainy |
| Rainy days | 13 days | |
| Humidity | 78% | 💦 very humid |
| Dew point | 22°C / 71°F | |
| Sunshine | 10.4 h/day | |
| Daylight | 12.4 h | |
| Wind | 30 km/h / 18 mph | |
| Air quality (US AQI) | 37 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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Hamilton in September — FAQ
- Is September a good time to visit Hamilton?
- September in Hamilton: hot, rainy, with clean air — a great time to visit. It ranks #6 of 12 months for Hamilton on SeasonMap's comfort score (78/100).
- What is the weather like in Hamilton in September?
- In September, Hamilton averages a daily high of 26.9°C and a low of 25.6°C, with about 116.4 mm of rain over roughly 13.2 rainy days.
- What is the air quality in Hamilton in September?
- Hamilton has a mean US Air Quality Index of about 37 in September.