Swiss glaciers lost more than 5 per cent of their volume after a winter with little snow and an exceptionally warm summer. The annual GLAMOS assessment puts the loss among the worst measured, with almost one-fifth of glacier volume gone in five years. Even high mountain ice thinned sharply, while several small glaciers disappeared.
Swiss glaciers lost more than 5 per cent of their volume in the latest annual assessment. GLAMOS measurements show that the combination of scant winter snow and exceptional summer warmth accompanied one of the largest losses recorded. Almost a fifth of the country’s glacier volume has disappeared in five years.[1], [2]
The winter from November 2025 to April 2026 ranked among the ten least snowy since measurements began. Warm, dry conditions then prevailed from May to September. The freezing level stayed above 4,000 metres on 76 days, more than twice the average. By September, hardly any snow remained on glaciers even at 3,500 metres, removing the protective cover that ordinarily delays ice melt.[1]
Average thinning reached 2.5 to 4 metres, with losses of 10 metres on some glacier tongues. Small glaciers including Bella Tola, Griessfirn and Plattalvafirn disappeared completely. The assessment estimates that melting glaciers supplied 2.2 trillion litres of water between July and September. That extra summer flow accompanies the depletion of the ice reserve; it cannot continue at the same level as the glaciers shrink.[1]
