Heatwave Forces Italian Guides to Suspend Mont Blanc Climbs as Alps Become Increasingly Unstable

An intense early-summer heatwave gripping Western Europe is rapidly changing conditions across the Alps, forcing mountain guides to suspend some of the continent’s most iconic mountaineering routes as thawing permafrost, melting glaciers, and frequent rockfall create increasingly dangerous conditions. On Italy’s side of Mont Blanc, professional guides in Courmayeur have stopped guiding clients on the mountain’s classic Italian normal route via the Miage Glacier, while Swiss guides have effectively abandoned the famous Hörnli Ridge on the Matterhorn until conditions improve.

The unprecedented decisions come as temperatures above 4,000 meters (13,120 feet) remain well above freezing, accelerating glacier melt and destabilizing mountain faces once held together by permanently frozen ground. “With the heat we had in June, conditions deteriorated quickly. It’s no longer safe enough to take clients up there,” Alex Campedelli, president of the Courmayeur Guides Society, told AFP. “The glacier is full of crevasses and it’s hard to find the right route. We decided last week we won’t sell that ascent to clients anymore.”

• Related: Czech Mountaineer Killed by Rockfall Near Zermatt, Switzerland

The affected route follows the Miage Glacier to the Gonella Hut before continuing toward the summit of Mont Blanc. Although technically more demanding than the famous French Goûter Route, it has long been one of the Alps’ classic high-mountain ascents, prized for its relative solitude and spectacular scenery. Today, however, the Miage Glacier bears little resemblance to the broad white highway climbers once crossed. Much of its surface is now covered in grey moraine, large crevasses have opened across the glacier, and guides say lengthy detours are now required simply to navigate safely. “We are overwhelmed by emergencies,” former Gonella Hut manager Davide Gonella told La Stampa. Water supplies at the hut have also become increasingly difficult as the retreating glacier no longer provides reliable meltwater.

There is currently no official closure of the route, but Italy’s professional guides have collectively decided they will no longer guide clients there until conditions improve. Guides from other nations are continuing tours, and sadly two Czech climbers lost their lives on Wednesday, July 15. The victims were identified as a 57-year-old IFMGA-certified mountain guide and his 49-year-old client. The guide and two clients were crossing the notorious Grand Couloir du Goûter, often referred to as the “Death Couloir,” when the trio was struck by falling rocks. The third member of their group survived with injuries.

The situation is equally concerning on the Matterhorn. Following two separate climbing accidents and continuing rockfall, the mountain guides of Zermatt have suspended guiding clients via the mountain’s famous Hörnli Ridge, the standard route first climbed by Sir Edward Whymper in 1865. “Everything is becoming unstable,” Cervinia mountain guide Laurent Nicoletta told La Stampa. “Until recently those rocks were held together by permafrost and were partially covered by snow and ice even in summer. After so many days of abnormal temperatures, rocks are beginning to move.”

While guides on Italy’s Lion Ridge continue to climb under carefully monitored conditions, they emphasize that ascents now require extremely early starts to avoid afternoon warming. Nearby, guides have also stopped guiding the Tiefenmatten Ridge on Dent d’Hérens after glacier retreat triggered landslides and left unstable rock towers hanging above the route.

For many skiers and mountaineers, glaciers receive most of the attention during heatwaves. But scientists say one of the biggest dangers lies beneath the surface. Much of the high Alpine rock has historically been cemented together by permafrost; ground that remains frozen year-round. As temperatures rise, that frozen “glue” melts, allowing previously stable rock faces to fracture and collapse. Researchers have increasingly linked warming temperatures with rising numbers of rockfalls throughout the Alps, particularly during prolonged summer heatwaves.

The effects are now being felt across Europe’s highest mountains. Pierre Mathey of the Swiss Mountain Guides Association told AFP: “On the Mont Blanc and Matterhorn routes, we simply need to have the humility to stop them for a while. This heatwave is dragging on and we’re seeing significant warming of the ground, snow and ice are melting, and the permafrost is thawing.”