Home to 1 in 4 people globally, the region should brace for “multi-hazards” and poor air quality apart from heat and water stress, according to a new report. The authors called on countries in the fractious neighbourhood to cooperate on data and form common solutions.

The monsoon season this year is likely to bring more water and heat stress, rather than relief, to South Asia, home to over two billion people – a quarter of the world’s population. 

This preliminary assessment comes from the Hindu Kush Himalaya Monsoon Outlook 2026 for June to September, which draws on global and regional climate outlooks for South Asia. 

The countries covered include Afghanistan, Bangladesh, Bhutan, China (the Xizang/Tibet Autonomous Region), India, Myanmar, Nepal, and Pakistan. Of these, much of Afghanistan and Myanmar are forecast to have a better, even above normal, monsoon in parts than the other countries. 

By contrast, the India Meteorological Department has forecast a below normal monsoon, at 92% average levels of 87 centimetres during 1971–2020 with a 5-percentage point error margin. 

The eight countries are members of the International Centre for Integrated Mountain Development (ICIMOD) based in Nepal, which produced this report; the other authors are from the Institute of Atmospheric Physics, Chinese Academy of Sciences (IAP-CAS). 

Worryingly, the ICIMOD’s report forecasts that temperatures will be about 0.5 to 2° above normal compared to a recent 15-year period, 2010-2024, which saw many of the hottest years on record. 

Threat of multi-hazards

A weaker monsoon does not reduce disaster risks, however, the report said. 

Floods account for a significant proportion of disasters in the Hindu Kush Himalaya region. The threat of floods and other water-induced hazards may be further amplified by the cascading nature of multi-hazards. 

In the HKH in particular, warmer temperatures, reduced snowfall, declining water availability, and lower river flows are likely to place additional stress on communities directly dependent on the monsoon. Erratic rainfall, especially after prolonged dry spells, can still trigger landslides and flash floods in mountain regions. 

In India, for example, between 2024 and 2025, more than 8,000 lives were lost due to disasters across Himalayan states, including Assam, Arunachal Pradesh, Himachal Pradesh, and Jammu and Kashmir.

The monsoon outlook “gives disaster management authorities a critical window to prepare,” said Navneet Yadav, Team Lead for Disaster Risk Reduction and Climate Resilience at Palladium India.

Air quality is also likely to take a hit. It is “logical” that a weaker monsoon will remove fewer pollutants from the air, the report’s authors said in response to a question from Health Policy Watch. 

“Warmer and drier conditions favour wildfires. Dust, ozone formation, et cetera,” said Saswata Sanyal, Disaster Risk Reduction Manager at ICIMOD. “So should the region be preparing for a poor air quality season, along with heat and water stress? Absolutely.”

The region is home to almost all of the world’s top 100 most polluted cities, making the waterfall effect on poor air pollution particularly dangerous. 

Impact of drier, hotter monsoon

The impacts are likely to extend beyond the mountains. 

Increasing temperatures, both maximum temperatures and night-time temperatures, may adversely affect human health due to heat stress people may face during heatwaves, particularly when combined with higher humidity. 

Heat stress occurs when the body cannot dissipate excess heat; when that happens, the body’s core temperature rises and the heart rate increases. 

Livelihoods will also be adversely impacted, according to the report. In agriculture, for instance, higher temperatures and lower water availability can lead to heat stress in crops and livestock, reduce yields, and shorten growing seasons, particularly in already marginal mountain farming systems. 

Elevated temperatures can also intensify evapotranspiration – evaporation from water bodies and transpiration from plants – and the loss of soil moisture, further compounding the impacts of droughts. 

Hydropower generation is also likely to decline, particularly in Nepal and Bhutan, which may further exacerbate existing stresses on national and regional energy supplies.

Can South Asia work together?

The risks are high, and so are tensions among several of the countries. ICIMOD may include representatives of all the region’s countries, but it is “apolitical”. The authors acknowledge that all countries “need to be on board” for data sharing to work.  

ICIMOD says it is trying to provide a platform where data generated by a monsoon or snow outlook can be used across borders, and be a space for countries to discuss these challenges and “form common solutions”.

Given the risk of hazards intensifying through the combination of above-normal temperatures and erratic rainfall, the report calls for better coordination to share relevant information quickly with disaster management networks.

“There is always some inhibition among the countries to share data openly with each other,” Sanyal said. “Obviously, you understand there’s a lot of politics involved.”