Climate Overview
The climate in Chamonix-Mont-Blanc is cool. The average annual temperature is 4°C and approximately 1910mm of precipitation falls per year. Chamonix-Mont-Blanc receives a notable amount of rainfall throughout the year, including during its driest month. Chamonix-Mont-Blanc is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: July, August, June. The coldest months are January, December, February, when temperatures can drop to -11°C. Chamonix-Mont-Blanc experiences heavy snowfall, typically from January through December.
Temperature
Temperatures in Chamonix-Mont-Blanc vary considerably across the year, with a 31°C difference between the coldest and warmest months. July is the warmest month, though highs remain moderate at 20°C with a mean of 15°C. The coldest month is January, when overnight lows fall to -11°C and the daily average is -7°C. On average, daily temperatures fluctuate by about 10°C between overnight lows and afternoon highs. The sharpest temperature change occurs between October and November, with a 7°C shift in average temperatures.
Precipitation
Chamonix-Mont-Blanc is a fairly wet location, receiving approximately 1910mm of precipitation annually, which averages out to around 159mm per month. The wettest month is December, averaging 220mm of rainfall. May and January also tend to see above-average precipitation. The driest month is April, with just 125mm. That's 95mm less than December, the wettest month. Rainfall is relatively evenly distributed throughout the year, so there is no pronounced dry or wet season to plan around. Chamonix-Mont-Blanc receives heavy snowfall, accumulating around 615cm annually from January through December. The snowiest month is January, with approximately 127cm. Winter travel should account for significant snow cover.
Wind
Chamonix-Mont-Blanc is relatively calm, with an average annual wind speed of 7km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is December, averaging 7km/h, though still comfortable for most outdoor activities. The calmest conditions occur in September, with average winds dropping to 6km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 1km/h between the calmest and windiest months.
Seasons
87 days until Summer
It is currently spring in Chamonix-Mont-Blanc, which began on March 20, 2026. Chamonix-Mont-Blanc is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in July at around 20°C, while the coldest stretch bottoms out in January near -11°C. Summer is next, beginning on June 21, 2026 — 87 days from now.
Spring
Temperatures range from -5 to 12°C. Rainfall is heavy, totalling around 496mm across the season with a monthly average of 165mm. Winds are generally light, averaging 7km/h. An umbrella or waterproof jacket is advisable as spring showers are frequent.
Summer
Temperatures range from 7 to 20°C. Rainfall is heavy, totalling around 444mm across the season with a monthly average of 148mm. Winds are generally light, averaging 7km/h. Comfortable clothing with a light layer for cooler evenings is all you need.
Autumn
Temperatures range from -5 to 14°C. Rainfall is heavy, totalling around 422mm across the season with a monthly average of 141mm. Expect around 98cm of snow accumulation during this period. Winds are generally light, averaging 7km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.
Winter
Temperatures range from -11 to 1°C. Rainfall is heavy, totalling around 548mm across the season with a monthly average of 183mm. Expect around 333cm of snow accumulation during this period. Winds are generally light, averaging 7km/h. Heavy layering and insulated outerwear are essential — exposed skin should be minimised outdoors.
Monthly Climate Data
The table below shows monthly climate averages for Chamonix-Mont-Blanc based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Snow is measured in centimetres (cm) and reflects average monthly snowfall accumulation. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.
