Switzerland’s Largest Glacier Records Biggest-Ever Melt in 2026 Due to Extreme Heatwave

In 2026, Switzerland experienced an unprecedented glacial melt, with its largest glacier, the Aletsch Glacier, recording its biggest-ever ice loss. This extreme melting event followed a winter with very little snowfall and a summer marked by record heatwaves across Europe.

Key Details of the 2026 Glacial Melt

Extent of Ice Loss

According to the Swiss Glacier Monitoring Network (GLAMOS), Switzerland's glaciers lost more than 5% of their total ice volume in 2026. Nationally, the average glacier thickness declined by 2.5 to 4 metres, with some glacier tongues experiencing ice losses up to 10 metres. Over the last five years, nearly 20% of Swiss glacier volume has disappeared.

Significance of the Aletsch Glacier

The Aletsch Glacier, situated in the Bernese Alps, holds the distinction of being the largest glacier in Switzerland by area and ice volume. Its record melt in 2026 highlights the alarming rate at which Alpine glaciers are retreating due to climate change.

Monitoring and Scientific Context

Role of GLAMOS

GLAMOS serves as Switzerland's national glacier monitoring network. It tracks key indicators such as glacier mass balance, changes in length, and ice volume using field surveys, aerial observations, and remote sensing. Matthias Huss, the GLAMOS director, characterized 2026 as an extreme year, continuing a trend of successive extreme melt events observed since 2022.

Other Affected Glaciers

Besides the Aletsch Glacier, prominent glaciers like the Rhône and Clariden also reported their greatest ice loss in 2026. Smaller glaciers such as Bella Tola and Griessfirn disappeared entirely in that year.

Environmental Impact and Concerns

Water Release and Consequences

Between May and September 2026, melting released approximately 2.2 trillion litres of water from Swiss glaciers. While this temporarily alleviated summer water shortages, the shrinking glacier mass poses long-term risks to regional water supplies and the Alpine cryosphere's future.

Wider Implications

The accelerated melting of glaciers in the Alps signals broader environmental challenges linked to climate change, including rising temperatures, altered precipitation patterns, and threats to mountain ecosystems.

Exam-Relevant Facts

• Aletsch Glacier is Switzerland's largest glacier located in the Bernese Alps.
• Glacier mass balance measures the gain or loss of ice and is key for monitoring glacier health.
• Swiss glaciers have lost nearly one-fifth of their volume in the last five years.
• GLAMOS is the official glacier monitoring body in Switzerland.
• Glaciers contribute vital water resources but are rapidly losing ice due to climate change.