Climate - Chamonix (France)

The climate of Chamonix is moderately continental, characterized by cold winters, with temperatures often below freezing (0 °C or 32 °F), and mild or pleasantly warm summers.
Chamonix-Mont-Blanc is a well-known ski resort, located at the foot of Mont Blanc (the highest mountain in the Alps with its 4,810 meters or 15,781 feet), in a valley at 1,000 meters (3,300 feet) above sea level, on the north-western slope of the Alps, in Haute-Savoie.
The average temperature of the coldest month (January) is of -1.8 °C (28.8 °F), that of the warmest month (July) is of 16.8 °C (62.2 °F). Here are the average temperatures.

Precipitation amounts to 1,280 millimeters (50.4 inches) per year. It ranges from 85 mm (3.3 in) in the driest months (February, March) to 130 mm (5.1 in) in the wettest (June). The summer is the rainiest season due to afternoon thunderstorms. Here is the average precipitation.

Winter is cold. Snowfalls are quite frequent. In periods of good weather, however, the sun can come out, while in the inland plains of France, in the Swiss plateau and in the Po valley, mists and cloud layers often form at low altitude.
Sometimes there can be cold spells, in which the temperature can drop down to -15 °C (5 °F) or even below. The coldest record is -25.4 °C (-13.7 °F) and was set in January 1966.
In summer, temperatures are pleasant and suitable for outdoor activities, although sometimes there can be rains and thunderstorms, and it can get very cool at night due to altitude.
Occasionally (but less than in the lowlands), there may be brief hot periods. On average, the temperature reaches or exceeds 30 °C (86 °F) for 8 days a year, but in recent years, hot spells are becoming more frequent due to global warming. The highest record is 37.2 °C (99 °F) and was set in July 1983.



On average, there are around 1,990 sunshine hours per year. Here are the average sunshine hours per day.

Best Time

The best time to visit Chamonix runs from June to August, since it is the mildest and sunniest period of the year. Sometimes, nights can be cool or even cold even in these months, so it can be useful to bring a sweatshirt or sweater and a jacket for the evening.

Chamonix - Weather by month

Based on the period 1991-2020

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In January, the coldest month of the year, the weather in Chamonix is usually very cold. The average temperature is of -1.8 °C (29 °F), with a minimum of -6.7 °C (19.9 °F) and a maximum of 3 °C (37.4 °F).
On the coldest nights of the month, the temperature usually drops to around -15.5 °C (4.5 °F). However, it dropped to -19.9 °C (-3.8 °F) in January 2005.
On the warmest days of the month, the temperature usually reaches around 10 °C (50 °F). However, it reached 15.3 °C (59.5 °F) in January 1998.
Precipitation amounts to 95 mm (3.7 in), distributed over 10 days.
The day lasts on average 9 hours and 10 minutes.
There are on average 3.5 hours of sunshine per day. So, the sun shines 40% of the time.
The average humidity is 70%.

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In February, the weather in Chamonix is usually very cold. The average temperature is of -0.2 °C (32 °F), with a minimum of -5.9 °C (21.4 °F) and a maximum of 5.5 °C (41.9 °F).
On the coldest nights of the month, the temperature usually drops to around -14.5 °C (6 °F). However, it dropped to -23.2 °C (-9.8 °F) in February 2012.
On the warmest days of the month, the temperature usually reaches around 14 °C (57.5 °F). However, it reached 19.6 °C (67.3 °F) in February 2011.
Precipitation amounts to 85 mm (3.3 in), distributed over 8 days.
The day lasts on average 10 hours and 25 minutes.
There are on average 4.5 hours of sunshine per day. So, the sun shines 42% of the time.
The average humidity is 72%. Hence, the air is normally humid.

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In March, the weather in Chamonix is usually cold. The average temperature is of 3.9 °C (39 °F), with a minimum of -2.5 °C (27.5 °F) and a maximum of 10.3 °C (50.5 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around -9.5 °C (15 °F). However, it dropped to -19.1 °C (-2.4 °F) in March 2005.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 19 °C (66 °F). However, it reached 22.1 °C (71.8 °F) in March 2004.
Precipitation amounts to 85 mm (3.3 in), distributed over 10 days.
The day lasts on average 12 hours and 0 minutes.
There are on average 5.5 hours of sunshine per day. So, the sun shines 44% of the time.
The average humidity is 73%. Hence, the air is normally humid.

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In April, the weather in Chamonix is usually quite mild. However, there are remarkable differences between night and day. The average temperature is of 7.4 °C (45 °F), with a minimum of 0.9 °C (33.6 °F) and a maximum of 14 °C (57.2 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around -5 °C (23 °F). However, it dropped to -8.8 °C (16.2 °F) in April 1993.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 22 °C (72 °F). However, it reached 26.4 °C (79.5 °F) in April 2011.
Precipitation amounts to 90 mm (3.5 in), distributed over 10 days.
The day lasts on average 13 hours and 35 minutes.
There are on average 5.5 hours of sunshine per day. So, the sun shines 42% of the time.
The average humidity is 75%. Hence, the air is normally humid.

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In May, the weather in Chamonix is usually mild. However, there are remarkable differences between night and day. The average temperature is of 11.8 °C (53 °F), with a minimum of 5.1 °C (41.2 °F) and a maximum of 18.4 °C (65.1 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around -1 °C (30 °F). However, it dropped to -4 °C (24.8 °F) in May 1991.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 26.5 °C (80 °F). However, it reached 31.7 °C (89.1 °F) in May 2009.
Precipitation amounts to 120 mm (4.7 in), distributed over 14 days.
The day lasts on average 14 hours and 55 minutes. So the days are long.
There are on average 6.5 hours of sunshine per day. So, the sun shines 44% of the time.
The average humidity is 77%. Hence, the air is normally humid.

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In June, the weather in Chamonix is usually very mild. However, there are remarkable differences between night and day. The average temperature is of 15.1 °C (59 °F), with a minimum of 8.1 °C (46.6 °F) and a maximum of 22.1 °C (71.8 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 2 °C (35.5 °F). However, it dropped to -2.3 °C (27.9 °F) in June 2006.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 30 °C (86 °F). However, it reached 33.1 °C (91.6 °F) in June 2016.
Precipitation amounts to 130 mm (5.1 in), distributed over 13 days.
The day lasts on average 15 hours and 35 minutes. So the days are long. June 21, the summer solstice, is the longest day of the year in the Northern Hemisphere.
There are on average 7.5 hours of sunshine per day. So, the sun shines 48% of the time.
The average humidity is 74%. Hence, the air is normally humid.

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In July, the warmest month of the year, the weather in Chamonix is usually very mild. However, there are remarkable differences between night and day. The average temperature is of 16.8 °C (62 °F), with a minimum of 9.4 °C (48.9 °F) and a maximum of 24.2 °C (75.6 °F).
On the coldest nights of the month, the temperature usually drops to around 4 °C (39.5 °F). However, it dropped to 1.1 °C (34 °F) in July 2000.
On the warmest days of the month, the temperature usually reaches around 31.5 °C (88.5 °F). However, it reached 35.7 °C (96.3 °F) in July 2015.
Precipitation amounts to 120 mm (4.7 in), distributed over 12 days.
The day lasts on average 15 hours and 10 minutes. So the days are long.
There are on average 8 hours of sunshine per day. So, the sun shines 53% of the time.
The average humidity is 71%. Hence, the air is normally humid.

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In August, the weather in Chamonix is usually very mild. However, there are remarkable differences between night and day. The average temperature is of 16.4 °C (62 °F), with a minimum of 9.1 °C (48.4 °F) and a maximum of 23.8 °C (74.8 °F).
On the coldest nights of the month, the temperature usually drops to around 3.5 °C (38.5 °F). However, it dropped to -1.7 °C (28.9 °F) in August 1995.
On the warmest days of the month, the temperature usually reaches around 31 °C (87.5 °F). However, it reached 34.4 °C (93.9 °F) in August 2012.
Precipitation amounts to 125 mm (4.9 in), distributed over 12 days.
The day lasts on average 14 hours and 0 minutes.
There are on average 7.5 hours of sunshine per day. So, the sun shines 52% of the time.
The average humidity is 73%. Hence, the air is normally humid.

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In September, the weather in Chamonix is usually mild. However, there are remarkable differences between night and day. The average temperature is of 12.8 °C (55 °F), with a minimum of 6.2 °C (43.2 °F) and a maximum of 19.4 °C (66.9 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 0.5 °C (32.5 °F). However, it dropped to -3.4 °C (25.9 °F) in September 1995.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 26 °C (79 °F). However, it reached 30.7 °C (87.3 °F) in September 2009.
Precipitation amounts to 105 mm (4.1 in), distributed over 10 days.
The day lasts on average 12 hours and 30 minutes.
There are on average 6 hours of sunshine per day. So, the sun shines 49% of the time.
The average humidity is 74%. Hence, the air is normally humid.

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In October, the weather in Chamonix is usually mild. The average temperature is of 9.0 °C (48 °F), with a minimum of 2.8 °C (37 °F) and a maximum of 15.1 °C (59.2 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around -3.5 °C (25.5 °F). However, it dropped to -8.5 °C (16.7 °F) in October 1997.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 23 °C (73 °F). However, it reached 26 °C (78.8 °F) in October 2012.
Precipitation amounts to 115 mm (4.5 in), distributed over 10 days.
The day lasts on average 10 hours and 55 minutes.
There are on average 4.5 hours of sunshine per day. So, the sun shines 41% of the time.
The average humidity is 72%. Hence, the air is normally humid.

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In November, the weather in Chamonix is usually cold. The average temperature is of 3.4 °C (38 °F), with a minimum of -1.5 °C (29.3 °F) and a maximum of 8.2 °C (46.8 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around -9 °C (16 °F). However, it dropped to -15.7 °C (3.7 °F) in November 1998.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 17.5 °C (63.5 °F). However, it reached 22.9 °C (73.2 °F) in November 2020.
Precipitation amounts to 100 mm (3.9 in), distributed over 10 days.
The day lasts on average 9 hours and 30 minutes.
There are on average 3 hours of sunshine per day. So, the sun shines 33% of the time.
The average humidity is 71%. Hence, the air is normally humid.

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In December, the weather in Chamonix is usually very cold. The average temperature is of -1.1 °C (30 °F), with a minimum of -5.2 °C (22.6 °F) and a maximum of 3 °C (37.4 °F).
On the coldest nights of the month, the temperature usually drops to around -14 °C (7 °F). However, it dropped to -20.9 °C (-5.6 °F) in December 2005.
On the warmest days of the month, the temperature usually reaches around 10 °C (50.5 °F). However, it reached 15.7 °C (60.3 °F) in December 2019.
Precipitation amounts to 110 mm (4.3 in), distributed over 11 days.
The day lasts on average 8 hours and 50 minutes. December 21, the winter solstice, is the shortest day of the year in the Northern Hemisphere.
There are on average 3 hours of sunshine per day. So, the sun shines 33% of the time.
The average humidity is 68%.