The Hindu Kush Himalaya (HKH) region has recorded its lowest snow persistence in 23 years, marking the third consecutive year of below-normal snowfall, according to ICIMOD’s 2025 Snow Update Report.

The alarming 23.6% decline in snow persistence—the fraction of time snow remains after falling—threatens water security for nearly two billion people dependent on 12 major rivers originating from the region.

Pema Gyamtsho, Director General of ICIMOD, called for urgent, science-based policies and cross-border cooperation: “Carbon emissions have already locked in an irreversible course of recurrent snow anomalies. We must adopt forward-looking strategies and regional collaboration to manage water resources and mitigate emissions.”

Seasonal snowmelt contributes significantly—up to 25%—to annual river flows, with western rivers more dependent than eastern ones. But consecutive meltwater shortages are now causing early-summer water stress, especially for downstream communities.

Sher Muhammad, ICIMOD’s Remote Sensing Specialist and lead expert for the report, highlighted an alarming trend: “Deficit snow years are now recurring. Each river basin must adopt localised responses, especially where snowmelt is critical for water supply.”

River Basins Hit Hard

The steepest drops in snow persistence were observed in:

Mekong: -51.9% (record low)
Salween: -48.3%
Tibetan Plateau: -29.1%
Brahmaputra: -27.9%
Yangtze: -26.3%
Ganges: -24.1%
Yellow River: -18.6% in 2025, following a peak of +98.2% in 2008
Indus: -16% in 2025, threatening water supply for 300 million people
Amu Darya: -18.8%
Helmand: -15.2%
Tarim: -4%, after six years of below-normal snow

The Yangtze, home to the Three Gorges Dam, saw its sixth-lowest snow level in 23 years, risking reduced hydropower output. The Ganges and Brahmaputra basins—vital for agriculture—are also among the worst hit.

The report urges basin-specific adaptive measures including: Seasonal water storage infrastructure, efficient use of meltwater, national preparedness plans for drought and snow anomalies and integration of snow data into water and energy strategies.

Experts stress that without coordinated action, the continued decline in snow could severely disrupt agriculture, hydropower, and ecosystem services across Asia.