Several of Switzerland's major glaciers, including the Rhône, Aletsch, and Clariden glaciers, experienced their most severe melting on record in 2026. The losses were even more dramatic for some smaller glaciers, which disappeared entirely. Among them were Bella Tola in the canton of Valais and Griessfirn in the canton of Glarus, both of which have now vanished permanently.

The scale of the decline is particularly striking over the past five years. During that relatively short period, Switzerland has lost nearly 20% of its total glacier ice volume, illustrating just how quickly the country's mountain landscapes are being transformed.

These findings come from the annual report of the Swiss Academy of Sciences (SCNAT), which draws on long-term glacier observations collected by the Glacier Monitoring Network, known as GLAMOS. The monitoring program is based at ETH Zurich and the universities of Fribourg and Zurich in Switzerland.

Extreme Summer Heat and Low Snowfall Accelerate Ice Loss

A combination of unusually little snowfall and prolonged summer heat contributed to the extensive melting. The winter of 2025 to 2026 ranked among Switzerland's ten least snowy winters since records began, leaving glaciers with less snow to protect them from warmer temperatures.

Conditions became even more unfavorable between May and September 2026, when persistent heat and dry weather accelerated ice loss, even at the highest elevations.

During the summer, the elevation at which temperatures reached freezing climbed above 4,000 meters on 76 days. That was more than twice the usual number of days and established a new Swiss record. By September, snow had disappeared even at elevations of 3,500 meters, exposing glacier ice that would normally remain protected beneath a layer of snow.

Melting Glaciers Provide Water, but the Supply Is Shrinking

The enormous amount of melting also temporarily helped ease Switzerland's summer water shortages. Between July and September, the country's glaciers released approximately 2.2 trillion liters of water, an amount exceeding four times the drinking water consumed by Swiss households in an entire year.

However, this additional water comes from a resource that is steadily disappearing. As Switzerland's glaciers continue to shrink irreversibly, the amount of meltwater they can provide will also decline, reducing a source of water that currently helps offset shortages during the warmer months.