88 kmTrail🇫🇷 Chamonix, France

Mont-Blanc 90K

Friday, 25 June 2027Estimated dateIn 8 months · Start 04:45

Official site

A semi-autonomous ultra on the high trails on both sides of the Chamonix valley, often between 2,000 and 2,500 m.

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Facts checked 10 Oct 2026 against marathonmontblanc.fr, marathonmontblanc.fr.

Elevation gain

6,200 m

Mountain · ↓ 6,200 m

Start altitude

1,041 m

above sea level, from terrain data

Temp at start

13°C

Peaks around 18°C

Entry fee

≈ $155

Lottery

Finishers

—

typical year

Course

Loop

24h cut-off

Getting thereFly into GVA (Geneva), about 68 km from the start

Course map

A detailed route is not available for this race yet. The marker shows the race location.

Elevation profile

Mountain: about 6,200 m of climbing and 6,200 m of descent. A detailed profile isn’t available for this race yet.

Race-day weather

At start

13°C

Peak during race

18°C

Humidity

80%

Chance of rain

10%

Wind

3 km/h

Race day in past years

Historical averages for 25 June ±3 days, 2016–2025, from 04:45 for 5 hours (70 days sampled). Source: Open-Meteo / ERA5.

What time could you run here?Adjust your goal time for this course’s hills and typical race-day weather.Race time calculator →

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<a href="https://irun42.com/race/mont-blanc-90k" title="Mont-Blanc 90K on iRun42"><img src="https://irun42.com/badge/mont-blanc-90k.svg" width="300" height="120" alt="Mont-Blanc 90K: course, elevation and race-day weather on iRun42" /></a>