Chamonix weather in September
Temperature, sea and sunshine in September: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in September
Good
Best time to visit: June – September
Best for skiing: December – March
What is the weather like in Chamonix in September?
In September, Chamonix is mild: daytime highs average 18 °C, and nights cool down to about 8 °C. Expect around 6 hours of sunshine a day. Rain is frequent, with about 13 rainy days and 112 mm in total. All in all, September is a good month for a holiday in Chamonix.
September compared
How the weather changes from August to October. Tap a month to open it.
| AugustAug | SeptemberSep | OctoberOct | |
|---|---|---|---|
| Score | 71 | 71 | 57 |
| Day | 22° | 18° | 14° |
| Night | 12° | 8° | 4° |
| Sun | 7 h | 6 h | 5 h |
| Rain days | 14 | 13 | 13 |
More details for September
- Daylight
- 12 h 37 min07:09 – 19:47
- UV index
- 5 · moderateclear sky, noon (estimate)
- Muggy days
- 0 daysdew point 18 °C or more
- Wind
- 8 km/haverage daily peak
- Cloud cover
- 58 %on average
- Hot days
- 0 days30 °C or more
- Snow days
- 0 days1 cm or more of fresh snow
- Time zone
- UTC+2Europe/Paris
How the score comes together
- Temperatureweight 50 %100 %
- Sunshineweight 20 %47 %
- Few rainy daysweight 30 %39 %
Each factor is rated from 0 to 100 % and weighted for the travel style “Mountain air”.
What to pack in September
- Sunscreen
- A jumper for the evenings
- Rain jacket or umbrella
Chamonix in September: quick answers
Is Chamonix hot in September?
No. In September, Chamonix is mild: daytime highs average 18 °C and nights drop to about 8 °C.
Does it rain much in Chamonix in September?
Rain is frequent, with about 13 rainy days and 112 mm in total.
Chamonix month by month
The whole year in ChamonixAll destinations: France
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, GeoNames (CC BY 4.0)