Mont-Blanc KM Vertical is the 3.8km vertical kilometre at Mont-Blanc Marathon 2026 (Chamonix, France). The race starts on June 26, 2026 at 04:00 PM. It starts in Chamonix and finishes in Planpraz.
Short race: go all out.
The course climbs 1000m+. With 263m/km of climbing, the course is exceptionally steep, with long hiking-grade sections. By gradient, 100% of the distance is uphill, 0% downhill and 0% flat. The longest climb runs 3.5km at an average 28.9% grade (1002m of vertical). The steepest climb averages 46.5% over 0.3km. Surface: 64% technical, 22% road, and 12% trail. Flat-equivalent effort: 11.8 FlatKM.
Trekking poles are strongly recommended: about 2.9km of the course is steep enough for them to pay off.
There is too little runnable descent to damage the quads: plan the race around climbing and fuelling.
On race day, start temperatures have historically ranged from 17°C to 28°C, with around 15°C at the highest point; the chance of precipitation is about 49%. Heavy rain of 10.0mm or more falls on about 8% of days around this date.
558 finishers completed the 2026 edition. Men's winner: Romain DISCHER (France) in 36:59. Women's winner: Christel DEWALLE (France) in 44:06.
This page has the full results and splits, a pacing and nutrition planner, a gradient matrix, an interactive elevation profile and historical weather for Mont-Blanc KM Vertical.
Other distances of Mont-Blanc Marathon 2026Mont-Blanc 90K (88.0km)·Mont-Blanc 42K (42.0km)·Mont-Blanc 23K (23.0km)·Mont-Blanc 10K (10.0km)
Other editions of Mont-Blanc KM Vertical2027
Official websitewww.marathonmontblanc.fr/en
