UTMB 2025 Kicks Off Amid Course Changes and Unsettled Weather

Chamonix, France - August 29, 2025 In a dramatic start to one of trail running’s most prestigious events, the 22nd Ultra-Trail du Mont-Blanc (UTMB) began this evening at 17:45 local time, featuring a revised course and challenging weather conditions.

Revised Route Following Rockfall Race organizers announced a modification to the early section between Chamonix and Les Houches after recent rockslides threatened runner safety. The new variant maintains the spirit of the original trail while avoiding unstable terrain, resulting in a final distance of 174 km with 9,900 m of positive elevation gain.

Cold Weather Kit Activated With forecasts calling for rain and temperatures dropping into the night, officials have activated the “cold weather kit” requirement. Runners must carry additional layers and waterproof gear to cope with wind chill and precipitation expected along several high-altitude passes.

Field of 2,000 Runners Sets Off Approximately 2,000 athletes from over 80 countries departed from Place du Triangle de l’Amitié in Chamonix, embarking on the now-iconic loop around Mont Blanc through France, Italy, and Switzerland. Elite contenders include multiple past champions and newcomers drawn by the UTMB’s status as the 100-mile final of the UTMB World Series.

First Finishers Anticipated Saturday Afternoon Despite the course revisions and adverse weather, the leading pack is projected to cross the finish line late Saturday morning into the early afternoon. Last year’s winner is absent, opening the door for contenders such as François d’Haene, Ludovic Pommeret, and Courtney Dauwalter to vie for victory.

Stay tuned for live updates as the race unfolds under the shadow of the Mont-Blanc massif, where endurance and adaptability will determine this year’s champions.