- Temperature
- -7 to 23°C
Updated July 2026 · Sources cited: weather-and-climate.com, climatestotravel.com
Good to know
Good to Know
- Chamonix is effectively several climates at once—the valley can be 5–20°C (41–68°F) warmer or colder than the same moment at higher elevations. Always check mountain conditions separately from town forecasts.
- Summer afternoons typically see convective thunderstorms building over ridgelines by mid-day. Plan high-altitude activities for morning hours.
- Winter valley floors are often chilly due to cold-air pooling despite sunny skies above—bring layers even on 'sunny' winter days.
- Precipitation is distributed fairly evenly year-round; there is no true dry season. Even July and August (summer peak) receive 115–130 mm per month, mostly as afternoon downpours.
- February is statistically the driest month and offers the clearest, sunniest ski days, despite being in peak season.
- November is widely considered the least favorable month: it sits between summer and winter seasons with unpredictable weather, fewer activities open, and many businesses closed.
- Snowfall above 2,000 m persists from November through May or later; higher slopes (3,300 m+) can receive snow even in summer.
Seasonal Periods
December to March
- Season
- Winter
- Rainfall
- High precipitation, mostly as snow at altitude. Valley receives 84–94 mm per month. Peak snowfall in December (245 mm).
- Character
- Cold, snowy, short daylight hours (roughly 8–9 hours). Sub-zero conditions reliable.
- Snowfall Relevant
- Abundant snowfall 2–6 meters per season depending on altitude. Snow persists from November to May+ at elevations above 2,000 m. Ski season runs mid-December to mid-April.
Temperature Peak And Trough
- Notes
- January is coldest month; valley temperatures often drop to -7°C (19°F) overnight. March sees slight warming.
Peak Daytime
- Amount Celsius
- 8
- Amount Fahrenheit
- 46
Trough Nighttime
- Amount Celsius
- -7
- Amount Fahrenheit
- 19
April to May
- Season
- Spring
- Rainfall
- High; 122 mm in May (frequent rain with mixed conditions). Highly unpredictable day-to-day.
- Character
- Transitional, unsettled. Rain increases, temperatures rise. Considered the most variable period.
- Snowfall Relevant
- Upper trails remain buried into May; lower elevations see rain. Mixed precipitation common.
Temperature Peak And Trough
- Notes
- Highly variable; May average highs 17°C (63°F), lows 4°C (39°F). April often cooler with possible snow above 2,000 m.
Peak Daytime
- Amount Celsius
- 17
- Amount Fahrenheit
- 63
Trough Nighttime
- Amount Celsius
- 4
- Amount Fahrenheit
- 40
June to August
- Season
- Summer
- Rainfall
- Counter-intuitive: wettest season in terms of rainfall amount (June 130 mm, July 119 mm, August 127 mm). Frequent afternoon convective thunderstorms. Despite daily rain frequency, sunny mornings common.
- Character
- Warm, humid, frequent afternoon storms. Long daylight (15+ hours in June). Most crowded season.
- Snowfall Relevant
- No snow at valley level. Above 3,300 m, snow possible even in summer.
Temperature Peak And Trough
- Notes
- Warmest season. July average high 23°C (73°F), August similar. Valley floor mild; high altitude remains cool.
Peak Daytime
- Amount Celsius
- 23
- Amount Fahrenheit
- 73
Trough Nighttime
- Amount Celsius
- 8
- Amount Fahrenheit
- 46
September to November
- Season
- Autumn
- Rainfall
- Decreasing as season progresses. October is one of driest months (119 mm). November wetter as snow returns to high altitude.
- Character
- Clear, cooler, quieter. Fewer tourists. November often considered least attractive (muddy, unpredictable).
- Snowfall Relevant
- First significant snowfalls dust slopes from October onward. November transitions to winter conditions.
Temperature Peak And Trough
- Notes
- September still mild (around 17°C (63°F)). October and November cool rapidly. First snowfalls on upper slopes by October.
Peak Daytime
- Amount Celsius
- 20
- Amount Fahrenheit
- 68
Trough Nighttime
- Amount Celsius
- 3
- Amount Fahrenheit
- 37
Best Months
July–August
- Activity Focus
- Hiking, climbing, sightseeing
- Reason
- Warmest, longest daylight, most activities fully open. Trade-off: highest rainfall, most crowded.
February
- Activity Focus
- Skiing, snowboarding
- Reason
- Driest month (84 mm), excellent ski conditions, brilliant clear days. High season pricing and crowds.
June, September–October
- Activity Focus
- Hiking, autumn scenery (Sept–Oct)
- Reason
- Moderate crowds, good weather, activities mostly open. June has afternoon storms; September–October cooler but clear.
Worst Months
November
- Activity Focus
- None particularly recommended
- Reason
- Between seasons; many businesses closed, unpredictable weather, muddy conditions. Not yet snowy enough for winter sports.
May
- Activity Focus
- Early season hiking (lower trails only)
- Reason
- Highest rainfall frequency (22 days with precipitation), variable conditions, not yet full summer.
Chamonix has a subarctic/alpine mountain climate with significant altitude-driven variation. The valley sits at 1,035 m, creating distinct microclimates: mild summers at lower elevations, severe winters with frequent snow at altitude, and high precipitation year-round.
Altitude Context
Temperature decreases ~6.5°C (44°F) per 1,000 m elevation gain. Valley (1,035 m) is warmer than high peaks. Temperature inversion common in winter (cold air pools in valley, warmer on slopes). This vertical variation creates effectively several climates stacked on top of each other.
Precipitation Annual
- Total Mm
- 1684
- Character
- High-precipitation climate; expect rain/snow 11–22 days per month depending on season.
- Distribution
- Fairly even year-round. Summer months concentrate rainfall as afternoon storms. Lowest rainfall in February (84 mm driest), December wettest (168 mm as snow).
- Total Inches
- 66
Peak And Off Peak Summary
- Peak Months
- July, August (summer tourism); December, January, February (ski season). June also busy.
- Off Peak Months
- May (shoulder season, quieter); November (between seasons, least favorable); April and October (moderate tourism).
- Shoulder Seasons
- April–May (spring), September–October (autumn) offer fewer crowds and moderate conditions.
AI-generated estimateData refreshed July 2026
Sources cited for this category
These are the sources cited in this climate & weather research for this city. Individual figures may not each trace to one of them.
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Data last updated July 2026 · Verify anything important.