Mt Everest snow line rises by 490 feet in less than two months, scientists warn of long-term shift

If seasonal snow persists long enough, it can eventually form glacial ice.

In a concerning sign of climate change impacts, the snow line around Mt Everest has risen by 490 feet in less than two months, scientists observed, according to a report by Times of India. The snow line, which was at 20,000 feet on December 11, 2023, had retreated to 19,510 feet by January 28, 2024, due to sublimation—a process where strong winds, low humidity, and unusually warm temperatures cause snow to evaporate directly into the atmosphere.

Glaciologist Mauri Pelto, a member of NASA Earth Observatory’s science advisory board, identified this change while analyzing satellite imagery and weather station data from the Everest region, the Times of India report stated. Scientists say drier and warmer conditions are driving the winter snow line higher, meaning snow now accumulates only at greater elevations.

According to NASA’s Landsat 9 satellite imagery captured on January 20, 2024, the snow retreat stands in stark contrast to typical patterns observed in January 2022. The Times of India report further noted that lower-elevation snow cover, which was once common, has become increasingly rare in recent winters. Pelto said this trend indicates a "new normal" for the region, emphasizing that the recent shift is primarily caused by sublimation rather than melting.

The Times of India report highlighted that the snow line was already above average at the start of this winter, following a dry beginning to 2024 and an unusually warm and wet post-monsoon season. Notably, 2022 was the only recent year when January snow lines remained at typical levels. However, similar elevations were recorded in January 2021, 2023, 2024, and now 2025, signaling a longer-term shift in snowfall patterns.

Unlike North American and European glaciers, which gain mass from winter snowfall, Himalayan glaciers rely on summer accumulation, with nearly 75% of annual precipitation falling during the monsoon season from June to September. If seasonal snow persists long enough, it can eventually form glacial ice. However, the rising winter snow line could disrupt this cycle, posing risks to water security for downstream communities and increasing wildfire threats, as seen in Nepal’s early 2025 fire season, experts warn.