Swiss glaciers set for second earliest 'loss day' on record

Researchers at the Swiss Federal Institute of Technology announced on Friday that Switzerland's glaciers will reach their "glacier loss day" on June 29, the second earliest date on record, as an exceptional heat wave sweeps across the Alpine nation. "According to our calculations and forecasts, glacier loss day this year will fall on June 29," glaciologist Matthias Huss said, noting that by this date all winter accumulation will have melted, leaving glacier ice directly exposed to further erosion.

Exceptional melt conditions

Huss told Swissinfo that the situation ranks as truly exceptional in the monitoring group's records. "The situation is truly exceptional. Only in 2022, when all glacier melt records were broken, did this day come earlier. Otherwise, this ranks second," he said, adding that the early date reflects months of unfavorable weather combined with persistent high temperatures.

Accelerating heat damage

The ongoing heat wave is rapidly stripping snow from the Great Aletsch Glacier, the largest ice field in the Alps, Huss reported on the social media platform X. "Within just two weeks, Konkordiaplatz on Great Aletschgletscher has gone from snow-covered to bare ice," he wrote. "It's the timing that is worrying. This should occur one to two months later in the season."

The scientist warned that Swiss glaciers are currently losing meltwater at a rate equivalent to filling an Olympic-sized swimming pool every six seconds. Huss said the early melt is not solely the result of current temperatures, noting that winter brought too little snow to provide adequate protection against the heat. "We've once again had a winter with too little snow, leaving glaciers with a weak protective layer," he said, adding that summer-like conditions reached 30°C (86°F) in the Swiss lowlands during May.

Summer projections

Looking ahead to the peak summer months, Huss warned that continued heat will drive irreversible ice loss across the Alpine glaciers. "All the high temperatures we are very likely to experience in July and August will lead directly to long-term glacier loss. We will certainly lose a large amount of ice this year," he said. The June 29 date falls just weeks after summer-like conditions reached 30°C in the Swiss lowlands during May, and follows the record-breaking melt year of 2022.