Chamonix weather in September
September in Chamonix: nice, rainy, with clean air — not the best time to visit.
#9 of 12 months in Chamonix · #595 of 604 destinations to visit in September · comfort 32/100 (tier F)
Updated June 2026 · climate normals from ERA5 reanalysis
Chamonix climate normals — September
| Daytime high | 20°C / 67°F | 😎 nice |
|---|---|---|
| Nighttime low | 10°C / 50°F | |
| Feels like (high) | 20°C / 68°F | |
| Rainfall | 119 mm / 4.7 in | 🌧 rainy |
| Rainy days | 15 days | |
| Humidity | 79% | 💦 very humid |
| Dew point | 11°C / 52°F | |
| Sunshine | 9 h/day | |
| Daylight | 12.5 h | |
| Wind | 6 km/h / 4 mph | |
| Snowfall | 10.2 cm / 4 in | |
| Air quality (US AQI) | 37 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Where is Chamonix?
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Chamonix in September — FAQ
- Is September a good time to visit Chamonix?
- September in Chamonix: nice, rainy, with clean air — not the best time to visit. It ranks #9 of 12 months for Chamonix on SeasonMap's comfort score (32/100).
- What is the weather like in Chamonix in September?
- In September, Chamonix averages a daily high of 19.5°C and a low of 10.1°C, with about 118.9 mm of rain over roughly 15.4 rainy days.
- What is the air quality in Chamonix in September?
- Chamonix has a mean US Air Quality Index of about 37 in September.
- Does it snow in Chamonix in September?
- Chamonix sees roughly 10.2 cm of snowfall in September.