The French Alps have expereienced a significant June heat wave that has driven a rapid rise in glacier snow lines. Rabatel et al (2013)  examined the equilibrium line altitude (ELA) of glaciers in the region from 1984-2010.  The ELA is the snowline at the end of the summer melt season.   Rabatel et al (2013) found the average snow line of 3000 m on Trient Glacier, 2900 m on Tour Glacier, and 2800 m on Argentiere Glacier.  

On June 7th, 2026 the snow line on Argentiere Glacier was near the terminus at 2300 m, by June 24th the snow line risen to 2700 m. This is 100 m shy of the average end of summer snow line. In 2015 and 2017 the snowline reached a record height of 2950 m in late August. This snow line rose to 3000 m again in August of 2022 and to 2900 m in August 2023. The snow lines from these years are in images below

The high snow lines result in a limited accumulation zone and an expanded ablation area leading to mass balance losses and terminus retreat. Argentiere Glacier is a World Glacier Monitoring Service reference glacier, with the data indicated in the images below. The glacier advanced from the early 1960s to early 1990s and since driven by negative mass balances in all but one year this century has retreated ~ 1 km. The mass balance loss has exceeded 1 m in most years this century and will again this year.