The best months to visit Chamonix are June, July, August and September, when average highs sit in the comfortable low-20s and the high peaks are reachable. August is especially pleasant, with an average high of 22.9 °C and just 12 rain days, while June warms to 20.9 °C and September eases back to 18.4 °C. July and August are peak season, crowded and pricey with French and European school holidays filling the valley. Winter (December to March) is the quiet alternative for weather tourists, though it draws its own ski crowds and December is the least sunny month.
Best months JuneJulyAugustSeptember
Chamonix month by month
Average highs and lows (°C), 2016–2025. Highlighted bars are the best months.
| Month | High | Low | Rain days | Sunshine | Days ≥30 °C | Crowds |
|---|---|---|---|---|---|---|
| January | 4 °C | -4.4 °C | 14 | ●●●●● | – | ●●●●● |
| February | 6.7 °C | -3.1 °C | 12 | ●●●●● | – | ●●●●● |
| March | 8.5 °C | -1.5 °C | 14 | ●●●●● | – | ●●●●● |
| April | 12.2 °C | 1.5 °C | 14 | ●●●●● | – | ●●●●● |
| May | 15.4 °C | 5.4 °C | 19 | ●●●●● | – | ●●●●● |
| June | 20.9 °C | 10.6 °C | 17 | ●●●●● | 1 | ●●●●● |
| July | 22.9 °C | 12.4 °C | 14 | ●●●●● | 1 | ●●●●● |
| August | 22.9 °C | 12.4 °C | 12 | ●●●●● | 1 | ●●●●● |
| September | 18.4 °C | 8.9 °C | 14 | ●●●●● | – | ●●●●● |
| October | 15.1 °C | 5.3 °C | 12 | ●●●●● | – | ●●●●● |
| November | 8.5 °C | -0.3 °C | 14 | ●●●●● | – | ●●●●● |
| December | 5.3 °C | -3.1 °C | 13 | ●●●●● | – | ●●●●● |
How the months are picked.A month qualifies when its average high sits in the comfortable 20–28 °C band (scored down towards 9 °C and 37 °C), rain days are few and sunshine hours are high — at least 78 % of the city's best-scoring month. July and August are then set aside as peak season (school-holiday crowds and prices) whenever at least three other months qualify; where summer is the only comfortable window they stay. Figures are ten-year averages (2016-01-01 to 2025-12-31) from ERA5 reanalysis data via Open-Meteo (CC BY 4.0) for the city centre coordinates. Sunshine is shown relative to the city's own year (modelled data overstates absolute hours).Heat and sea: days with a high of 30 °C or more are averaged over 2016–2025 (ERA5).Crowds:Relative to an average month in the same region (Eurostat nights spent at tourist accommodation, by NUTS 2 region and month) — a measure of season, not of how crowded one city is compared with another. Busiest month August, quietest November; NUTS 2 region FRK2, 2022–2025, Eurostat.
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When to go, and what to expect
Spring (Mar–May)
A transitional lull — fine for valley walks but high trails and lifts may still be closed.
Summer (Jun–Aug)
The prime window for hiking, cable cars and clear views; June is the calmer choice.
Autumn (Sep–Nov)
September is a standout — warm, scenic and less crowded than midsummer.
Winter (Dec–Mar)
Worth it for skiers and snow lovers, but not for comfortable sightseeing.
Notable events
- December to April
- Chamonix ski and alpine winter season
- Late July to early August
- Cosmojazz Festival
- August
- Fête des Guides (Mountain Guides Festival)
- Late June
- Marathon du Mont-Blanc
Frequently asked
Is Chamonix too hot in August?
No. August averages a high of 22.9 °C with cool nights around 12.4 °C, and at 12 rain days it is one of the drier summer months — comfortable for hiking and cable-car trips.
What is the rainiest month in Chamonix?
May is the wettest, with 19 rain days. Early summer stays damp too — June has 17 rain days — while August drops to 12.
Is winter worth visiting?
For skiing, yes. Winter is cold, with January highs of 4 °C and lows of -4.4 °C, and December is the least sunny month — great for snow sports but not for valley sightseeing.
Know when to go? Now decide where to stay — our Chamonix area guide →
Areas of Chamonix
Best time to visit near here
Sources
- Open-Meteo historical weather API — monthly climate normals, 2016–2025 (CC BY 4.0)
- ERA5 reanalysis (ECMWF / Copernicus) — the underlying temperature, precipitation and sunshine data
- ReasonStay methodology — how the best months are computed and checked
An independent guide to Chamonix — honest, verified, no invented data. Climate figures: ERA5 via Open-Meteo, 2016–2025 averages; the best months are computed from them, not opinion.