Swiss glaciers lost 5.5% of ice volume in 2026: what to know

How did snow and heat combine to drive the loss?

Winter snowfall was unusually sparse. Snow shields glacier ice from warmth; snow that remains can also accumulate and eventually form new ice. With less cover, bare ice was exposed for longer, leaving the glaciers more vulnerable to the heat that followed.

Heat waves from May through September then sustained the melting. The monitoring network identifies both the thin winter snowpack and the prolonged heat as leading reasons for the year’s loss. It does not assign a separate share of the national decline to either factor.

The effects varied across glaciers. The Swiss research and science bodies reported average thickness losses of 2.5 to 4 metres on individual glaciers, with losses reaching about 10 metres on some glacier tongues. Those measurements describe thinning at particular sites, not a uniform loss across every Swiss glacier.

The sequence matters: a snowy winter can protect ice into the warmer months, while a thin snowpack leaves less protection when temperatures rise. In 2026, the glaciers faced both a poor start to the melt season and sustained summer heat.

What does the melt mean for summer water?

The roughly 2,200 billion litres lost from July through September show the scale of the seasonal melt. That water was not a permanent addition to Switzerland’s supply, nor does the figure mean it was available for household use.

Glacier meltwater flows downstream and helps ease summer water shortages. But a glacier that has less ice-covered area has a diminished capacity to provide that relief, the monitoring bodies said. Heavy melting in one summer can therefore coincide with a weaker water buffer in years ahead.

The monitoring report identifies irrigation and hydropower among the uses for which changing glacier-fed flows matter. Switzerland generates more than half its electricity from hydropower, the Associated Press reported. The findings do not quantify how future water flows or hydropower will change for particular communities.

Was 2026 the worst year for Swiss glaciers?

Not by annual percentage loss: 2022 remains the record year. The monitoring network also found that Switzerland lost less ice by volume in 2026 than in 2003, even though the 2026 percentage decline was greater. There was substantially less glacier ice left to lose.

That distinction does not make the latest loss less consequential. Nearly a fifth of Swiss glacier ice volume has disappeared over five years, reducing the ice that can contribute meltwater during future summers.

Matthias Huss, who heads the monitoring network, attributed current warming to human-caused climate change and told the Associated Press that reducing carbon dioxide emissions would help glaciers. For downstream water users, the immediate finding is that the glaciers’ contribution during summer shortages is already declining.