Last updated: March 2, 2024
The weather in Chamonix-Mont-Blanc, France, during September is characterized by an average temperature of 10°C (49°F). Highs can soar to 20°C (69°F), while lows may dip to -1°C (30°F). Typically, the humidity level in Chamonix-Mont-Blanc throughout September hovers around 73%.
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Humidity
In September, Chamonix-Mont-Blanc averages 109 mm (4.3 inches) of rainfall, typically over the course of 16 rainy days. The month enjoys an average of 12 hours 29 minutes of daylight, with the sun shining for approximately 11 hours 1 minutes each day. Additionally, there is a 30% probability of sunny days during this period.
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In September, the UV Index in Chamonix-Mont-Blanc reaches a maximum of 7, indicating a level of High exposure. The most intense UV radiation typically occurs between 13:00 and 15:00, during which unprotected skin may burn in as little as 25 minutes.
| 07:00 | 08:00 | 09:00 | 10:00 | 11:00 | 12:00 | 13:00 | 14:00 | 15:00 | 16:00 | 17:00 | 18:00 | 19:00 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UVI | 1 | 1 | 2 | 3 | 5 | 6 | 7 | 7 | 6 | 4 | 3 | 1 | 1 |
| Exposure | Low | Moderate | High | Moderate | Low | ||||||||
| Time to burn | 45 min | 30 min | 25 min | 30 min | 45 min | ||||||||