According to a report published by PERMOS on Monday, 2015 in Switzerland was the hottest year on record.
This, coupled with persistent mild weather in Switzerland over the past few years, led to “exceptionally high” temperatures of Swiss permafrost during the 2014/15 monitoring period.
A permanently frozen part of the ground, permafrost covers around five percent of Switzerland, usually alpine regions above 2,500m, and depends largely on ground temperatures.
Since 2009 ground temperatures in the country have been above average, said the report.
Measurements taken from some 30 locations in Switzerland, including the Murtel-Corvatsch glacier and the Schilthorn, showed that permafrost temperatures reached a new high in 2015.
They also showed an increase of water in the permafrost, a sign of melting.
The elevated temperatures of exposed rockfaces led to an increased number of rockfalls in July and August 2015, said the report.
Hot weather has also affected the speed of glacial movement, which increased by an average of 20 percent compared with the previous year.
Many glaciers can move several metres a year, it added.
The news comes after Switzerland experienced spring-like conditions on Sunday, with a mini heatwave and clear skies leading record numbers to the ski slopes.
MeteoSuisse recorded temperatures of 17.4C in Geneva and 16C in Basel. Even the ski resort of Crans-Montana in the canton of Valais reached 10C.
The good weather and the end of the February school holidays brought record numbers to resorts including Leysin and Verbier, said news agency ATS.