Switzerland's glaciers are expected to exhaust all their winter snow reserves by Monday, June 29, reaching a grim milestone known as "Glacier Loss Day" — the second-earliest such date on record. From that point forward, every drop of meltwater will directly erode glacier mass, shrinking the ice fields of the Swiss Alps through the remainder of the summer.
A Year That Mirrors 2022
According to ETH Zurich and Glacier Monitoring in Switzerland (GLAMOS), June 29 marks the day when the snow accumulated over the past winter will have been fully offset by melting in lower-lying glacier zones. The only year the tipping point arrived earlier was 2022, when it fell on June 26 — a year GLAMOS network chief Matthias Huss described as "by far the most extreme year ever recorded in the Alps".
Huss told AFP that 2026 had been "surprisingly similar" to that record-setting year. This year's glaciers received roughly 25 percent less fresh snowfall than the 2010–2020 average, and a warm May accelerated the disappearance of the snowpack. A Saharan dust event in March further darkened glacier surfaces, reducing their ability to reflect sunlight. Once the white snow cover is gone, the exposed gray ice absorbs radiation more quickly, creating a feedback loop that accelerates melting.
A Continent Under Extreme Heat
The early arrival of Glacier Loss Day has been compounded by a deadly heatwave sweeping across Europe. The World Health Organization reported more than 1,300 excess deaths across Europe since June 21. Germany recorded its highest-ever temperature at 41.3°C, while records also fell in Belgium and the Netherlands. Researchers from World Weather Attribution said the heat would have been "virtually impossible" without human-caused climate change.
Huss, who recently visited the Rhone Glacier, said he observed a meter of vertical ice loss in just 10 days. "We are three months too early compared to a healthy state," he said. On average this century, Glacier Loss Day has not arrived until mid-August.
A Narrowing Window
The volume of Swiss glaciers shrank by 38 percent between 2000 and 2024, and Switzerland has lost some 1,200 glaciers in the past 50 years, leaving roughly 1,300 remaining. As glaciers retreat, they contribute less meltwater to major rivers like the Rhine and the Rhone — a shift that researchers warn will worsen as ice masses continue to shrink.
"If warming continues as it did over the last decades, by 2100 we will only be left with some little remnants of ice," Huss said.