Swiss glaciers suffer 4th-largest ice loss in 2025 due to lighter snow, heat waves

The melting of glaciers in Switzerland was once again "enormous" in 2025, according to the Swiss Glacial Measurement Network (GLAMOS) and the Swiss Commission for Cryosphere Observation of the Swiss Academy of Natural Sciences.

The GLAMOS said in a statement on Wednesday that a snow-poor winter combined with heat waves in June and August resulted in a 3% loss of glacier volume, the fourth-largest decline since records began.

The ice mass has shrunk by a quarter over the last 10 years. Even during the UN International Year for the Preservation of Glaciers, the pattern continued. Heat waves in June brought glaciers dangerously close to record losses in 2022, it said, and by mid-July, the winter's snow reserve had melted.

Cooler weather in July provided some relief, but it was insufficient to prevent Switzerland's 3% volume loss this year, which ranks fourth behind 2023, 2022, and 2003.

Especially glaciers below 3,000 meters suffered, with thickness declines of over two meters at Claridenfirn, Glacier de la Plaine Morte, and Silvretta Glacier. In southern Valais, including the Allaling and Findel Glaciers, losses were nearly one meter lower, the GLAMOS said.

The winter of 2024-2025 saw very little precipitation and the third-warmest half-year on record, leaving snow amounts at historic lows. The second-warmest June further accelerated melt, while an August heat wave pushed the zero-degree limit above 5,000 meters, according to the findings.

"The constantly dwindling glaciers are helping the mountains to destabilize," Matthias Huss, head of GLAMOS, said. "This can lead to events like those in the Lötschental, where a rock-ice avalanche buried the village of Blatten in May."