The second-worst year

The winter of 2025/26 left 25% less snow than usual on Swiss glaciers. From May to September, long heat waves followed one another with hardly a break; June to August was the hottest summer on record in Switzerland.

Glaciers lost 5.5% of their volume in the hydrological year 2025/26, with an average mass balance of −2.86 m water equivalent. Only 2022 was worse. For four large glaciers, the Allalin, the Clariden, the Great Aletsch and the Rhône, 2026 was the most negative year ever measured, worse even than 2022.

About 42.6 km³ of ice remain, and the glaciers cover some 714 km², a third less than in 2000. The ten years to 2026 removed 27% of the ice. Since 2021 almost a fifth of all Swiss glacier ice has gone; the melt of 2022–2026 was more than twice that of any earlier five-year period on record.

Even so, the 2.5 km³ of ice lost in 2026 was less water than the 2003 heatwave released: there is less and less ice left to melt. GLAMOS again concludes that the peak of meltwater from Swiss glaciers has likely passed.