In a concerning climate signal all three major river basins of the Indian Subcontinent the Ganga Indus and Brahmaputra are witnessing their steepest declines in snow persistence, a new report warns. The findings, released by the International Centre for Integrated Mountain Development (ICIMOD) on April 21, 2025, reveal that the Hindu Kush Himalaya (HKH) region is experiencing its third consecutive below-normal snow year.
Snow persistence defined as the duration snow remains on the ground after snowfall is a key indicator for seasonal water availability. A drop in this metric threatens water security for millions, as snowmelt feeds major rivers across South Asia.
The Ganga basin, which saw its highest snow persistence of +30.2% in 2015, has plummeted to a 23-year low of -24.1% in 2025. The Indus basin, which held steady until 2020 with a peak of +19.5%, declined sharply to -27.9% this year, marking its worst performance in two decades. The Brahmaputra basin also saw a worrying drop from +27.7% in 2019 to -27.9% in 2025 raising concerns about future hydropower production and agricultural impacts.
The Tibetan Plateau, source to many of North India rivers experienced an extreme shift in snow persistence from +92.4% in 2022 to -29.1% in 2025. ICIMOD called this “a stark indication of the plateau’s climate sensitivity.”
The HKH Snow Update Report 2025 identifies the Mekong and Salween basins as experiencing the most severe anomalies, with snow persistence declines of -51.9% and -48.3% respectively. These are followed by the Tibetan Plateau (-29.1%), Brahmaputra (-27.9%), Yangtze (-26.3%), and Ganga (-24.1%).
Such persistent deficits in snow cover translate to reduced meltwater in early summer, leading to lower river flows, threatening agriculture, energy generation and drinking water supplies particularly for the nearly 300 million people dependent on these rivers.
ICIMOD’s 23-year analysis (2003–2025) of the snow season from November to March paints a grim picture of accelerating climate impacts in the region. The report urges regional governments to act swiftly by strengthening water management systems, developing drought preparedness strategies, investing in seasonal water storage, and building cooperation across borders.
“Long-term resilience,” the report concludes, “depends on forward-looking, science-driven policies that prioritize efficient meltwater use and integrated water management in a changing climate.”