Switzerland Glaciers Lose Nearly 20% of Ice in Five Years As Record Heat Accelerates Melting

Switzerland lost more than 5% of its glacier ice volume in 2026, bringing the country’s total losses over the past five years to nearly 20%, according to monitoring data published by the Swiss Glacier Monitoring Network (GLAMOS) on Oct. 1. Unusually low snowfall during the winter of 2025-2026, followed by persistent heat and dry conditions between May and September, accelerated melting, while several smaller glaciers disappeared completely.

The rapid decline threatens a natural water reserve that helps Switzerland manage shortages during summer. Although melting glaciers released around 2.2 trillion liters of water between July and September 2026, researchers warn that this temporary supply will shrink as the glaciers continue to lose ice.

Some Swiss Glaciers Have Disappeared Completely

The 2026 figures show that the damage extends beyond gradual retreat. The Rhône, Aletsch and Clariden glaciers experienced their greatest melting on record, according to findings published by ETH Zurich and based on the annual report of the Swiss Academy of Sciences.

The average thickness of Swiss glaciers fell by 2.5 to 4 meters during the year. In some lower glacier sections, known as glacier tongues, the ice loss reached as much as 10 meters.

Two smaller glaciers, Bella Tola in the canton of Valais and Griessfirn in the canton of Glarus, disappeared completely and permanently. Their loss illustrates how smaller ice bodies can vanish as warmer conditions reduce the snow and ice that sustain them.

Although the country’s overall losses did not quite match the record melting recorded in 2022, the cumulative decline remains severe. Nearly one-fifth of Switzerland’s glacier volume has disappeared since 2021.

The findings come from long-term measurements collected by GLAMOS, which works with ETH Zurich and the universities of Fribourg and Zurich. The data form part of the Swiss Academy of Sciences’ annual assessment of glacier conditions.

Record Heat and a Snow-Poor Winter Drove the Losses

The melting accelerated because glaciers received little fresh snow during winter and faced unusually warm conditions during the following summer.

The winter of 2025-2026 was among Switzerland’s 10 least snowy winters since measurements began. Snow normally provides a protective layer over glacier ice, reflecting sunlight and delaying the exposure of darker ice to warmer air.

Conditions worsened from May through September, when hot and dry weather increased melting at high elevations. The freezing level, the altitude above which temperatures generally remain below freezing, rose above 4,000 meters on 76 days during the summer. That was more than twice the usual number and a new Swiss record.

By September, snow had disappeared even at elevations of 3,500 meters. Without that protective covering, glacier ice was exposed directly to conditions that accelerated its loss.

Melting Temporarily Supplies Water but Weakens Future Reserves

Glacier meltwater helped ease Switzerland’s summer water shortages in 2026. Between July and September, the glaciers released approximately 2,200 billion liters of water, equivalent to more than four times the annual drinking-water consumption of Swiss households.

That large volume highlights the importance of glaciers as natural water stores. They accumulate snow and ice during colder periods and release water as temperatures rise, helping support supplies during dry months.

However, the benefit comes at a cost when melting exceeds the amount of ice and snow that glaciers can recover. As their total area and volume shrink, they have less stored water available to release in future summers.

The latest measurements therefore point to a long-term concern beyond the loss of ice-covered mountain landscapes. Switzerland could receive less meltwater from its glaciers as its natural reserves continue to diminish.

The 2026 results show how a winter with little snow followed by months of extreme heat can accelerate glacier loss within a single year. With nearly 20% of its glacier volume gone in five years, Switzerland faces a continuing challenge as warming conditions reshape its mountain environment and reduce a key source of seasonal water.