Matterhorn and Mont Blanc routes suspended as heat destabilizes Alpine peaks

Rising summer temperatures are melting permafrost on the highest summits of the Western Alps, making rock faces unstable and increasing rock‑fall risk. Swiss guides in Zermatt have halted the normal Matterhorn route over the Hörnligrat after two climbers died when a falling rock caused their rope team to plunge from about 4,030 m. Italian mountain‑guide associations have likewise withdrawn the classic normal routes on Mont Blanc via the Miage glacier and on the Dent d’Hérens via the Tiefenmatten ridge, citing dangerous conditions.

Guides advise alpinists to start early, stay in the shade, and avoid the most exposed sections. Temperatures of 8‑12 °C have been recorded at 3,000 m, with the zero‑degree line now around 4,400 m, accelerating glacier melt and exposing new crevasses. The closures affect popular climbing itineraries across the Swiss‑Italian border and underscore growing safety concerns linked to climate‑induced changes in high‑mountain environments.