Kathmandu- Communities across the Hindu Kush Himalayan (HKH) region face an increased risk of flash floods, landslides and glacier-related disasters this monsoon despite forecasts of below-normal seasonal rainfall, scientists have warned.

The warning comes after deadly cloudburst-triggered flooding in Pakistan’s Gilgit-Baltistan and intense rainfall that caused flooding in Arunachal Pradesh, India, even as the HKH Monsoon Outlook 2026 projects below-average rainfall across much of the region.

According to the International Centre for Integrated Mountain Development (ICIMOD), this year’s monsoon is expected to be characterised by prolonged dry spells interrupted by short bursts of intense rainfall capable of triggering destructive flash floods, landslides and debris flows.

“The biggest misunderstanding is that less seasonal rainfall means lower flood risk,” said Saswata Sanyal, Disaster Risk Reduction Specialist at ICIMOD. “Seasonal forecasts describe average conditions over several months, not what happens in a single valley. Under El Niño, long dry spells can be interrupted by intense local storms that trigger devastating flash floods and landslides.”

Scientists said the apparent contradiction stems from the influence of El Niño, which is expected to suppress seasonal rainfall across much of South Asia while allowing short-lived weather systems to generate highly localised but intense downpours.

As a result, the monsoon is becoming increasingly erratic, with extended dry periods placing pressure on agriculture and water supplies while isolated heavy rainfall events continue to threaten lives, property and critical infrastructure.

Experts also warned that above-normal temperatures are likely to heighten risks across glacier-fed river basins, including the Indus, Ganga and Brahmaputra systems. Warmer conditions accelerate glacier and snowmelt, increasing river flows during heavy rainfall while destabilising mountain slopes and moraine-dammed glacial lakes.

“The recent flooding in Pakistan’s Thore Valley demonstrates that hazards in the HKH are no longer occurring in isolation,” said Manish Shrestha, Hydrologist at ICIMOD. “Heavy rainfall, glacier melt, unstable slopes and fast-rising rivers can interact to create cascading disasters. Preparedness must reflect these compound risks rather than treating each hazard separately.”

ICIMOD urged governments to prepare simultaneously for drought, heat stress, flash floods, landslides and glacier-related hazards instead of addressing each risk independently.

The organisation said particular attention should be given to communities living along riverbanks, on steep mountain slopes and in rapidly expanding urban areas across Nepal, northern and north-eastern India, Pakistan and other vulnerable mountain regions, where fragile geology, rising temperatures and expanding infrastructure continue to increase disaster exposure.

Neera Shrestha Pradhan, Water and Disaster Risk Reduction Lead at ICIMOD, said combining scientific forecasting with local knowledge would become increasingly important as rainfall patterns grow more unpredictable. She noted that settlements located on steep slopes and along riverbanks remain among the most vulnerable during this year’s monsoon.

Qianggong Zhang, Head of Climate and Environmental Risks at ICIMOD, said disasters across the HKH are becoming more frequent and increasingly complex, while preparedness systems remain focused on individual hazards. He stressed the importance of strengthening transboundary early warning systems and information sharing to better manage risks that extend across river basins and national borders.

Navneet Yadav, Team Lead for Disaster Risk Reduction and Climate Resilience at Palladium India, said heavy rainfall in Himalayan headwaters can rapidly translate into downstream flooding, making continuous monitoring of upstream conditions essential for reducing flood risks across entire river basins.

With several weeks of the monsoon season still remaining, scientists cautioned that below-normal seasonal rainfall should not be interpreted as a reduced disaster risk. Instead, they urged authorities and communities to remain prepared for both prolonged dry conditions and sudden extreme rainfall events throughout the season.