Kathmandu, February 21, 2025 – Snow cover atop Mount Everest has retreated by 150 metres, signaling a lack of snow accumulation during the winter of 2024-25, researchers have observed.
Rising Snow Line Signals Climate Shift
NASA satellite images from October 2023 to early January 2025 reveal a steady rise in the snow line, glaciologist Mauri Pelto wrote in a blog post on February 2. This trend, seen in both 2024 and 2025, suggests that snowfall is failing to persist, even at high elevations.
Mount Everest, at 8,849 metres, is the highest point on Earth, straddling Nepal and Tibet. The snow line marks the elevation where snow remains permanently. A rising snow line indicates melting at lower altitudes, a sign of warming temperatures and drier conditions.
Persistent Warmth and Dryness Accelerating Snow Loss
Pelto noted that recent winters, including those in 2021, 2023, 2024, and 2025, have been warmer and drier, leading to shrinking snow cover, higher snow lines, and increased forest fires. Despite occasional snowfall, the lack of persistent snow has caused glaciers to retreat even above 6,000 metres.
The primary factor behind snow loss at these extreme altitudes is sublimation, where ice evaporates directly into the air. This process leads to daily losses of up to 2.5 millimetres, accelerating glacial retreat.
Severe Drought and Rising Temperatures in Nepal
Nepal experienced 20-25% of normal precipitation in December 2024, with drier conditions in the east and above-average temperatures. This led to extreme drought in several provinces, including Koshi Province.
By January 28, 2025, the average snow line on Everest Region glaciers had reached 6,100 metres, a 150-metre rise from December 11, 2024. Pelto emphasized that this winter was different from 2020-21, when high snow lines resulted from an extraordinary January heat wave. This time, the key factors were above-normal temperatures and an absence of significant precipitation.
At Everest Base Camp, snowfall was less than 25 millimetres from January to March 2024, marking one of the driest periods on record. If these conditions persist, experts warn that the Himalayan glaciers could face irreversible damage.
