Snow persistence in Hindu Kush hits 23-year low, South Asia's water security at risk: Report

New Delhi: Snow persistence -- or snow that usually stays on the ground between November and March -- was 23.6 per cent below normal levels in the Hindu Kush Himalaya (HKH) region this year, a record low in the last 23 years, according to a new report.

This marks the third consecutive year of below-normal seasonal snow across the region, the International Centre for Integrated Mountain Development (ICIMOD), an intergovernmental body, said in the 2025 HKH Snow Update report published on Sunday.

Snow that typically remains on the ground during winter months has been melting faster or not falling in expected amounts. This snowmelt is a crucial water source for rivers, especially during the dry season.

The sharp drop in snow levels across the region could seriously affect water supply to nearly two billion people in India and neighbouring countries.

ICIMOD's Director General Pema Gyamtsho said, "Carbon emissions have already locked in an irreversible course of recurrent snow anomalies in the HKH."

"To tackle this regional snow crisis and the challenges it creates for long-term food, water and energy resilience, we urgently need to embrace a paradigm shift toward science-based, forward-looking policies and foster renewed regional cooperation for transboundary water management and emissions mitigation," Gyamtsho said.

Sher Muhammad, remote sensing specialist at ICIMOD and the lead expert for the report, said, "We are observing such deficit situations occurring in continuous succession. This is an alarming trend. While our findings give a broad picture across the region, each must act based on the specific conditions of their river basins, particularly where seasonal snow melt is the major water source."

On average, snowmelt contributes about 23 per cent to the total yearly water flow in major river basins. But this year, snow persistence was 23.6 per cent below normal levels, the lowest recorded in the past 23 years, according to ICIMOD.

All 12 major river basins in the region, including those in India, China, Pakistan, Afghanistan and Southeast Asia, have recorded below-normal snow levels this year. The situation is especially dire in the Mekong and Salween basins, which recorded snow persistence levels 51.9 per cent and 48.3 per cent below normal, respectively.

In India, the Ganges and Brahmaputra river systems have witnessed significant snow deficits.

The Ganges basin experienced its lowest snow persistence in over two decades, at 24.1 per cent below normal, which means less snowmelt will be available in early summer, a time when demand for farming and drinking water is high.

Snow persistence dropped 27.9 per cent below normal in the Brahmaputra basin, which could hit hydropower generation and agriculture hard.

The Indus basin, which supports millions of people in India and Pakistan, also reported a continued decline in snow cover. While the drop in 2025 was slightly less severe than in 2024, snow persistence remained 16 per cent below normal.

ICIMOD experts warned that if this trend continues, the region could face more frequent water shortages, forcing greater reliance on groundwater and raising the risk of droughts.

They suggested that governments and water agencies must act swiftly by preparing water-saving plans, improving drought response, and using scientific data to manage resources more effectively.