Hindu Kush Himalaya (HKH) monsoon outlook 2025

The Hindu Kush Himalaya (HKH) region is highly susceptible to the influence of monsoon, a periodic wind system, especially in the Indian Ocean and southern Asia. The summer monsoon, between June and September, is the major source of precipitation in the region with significant impacts on the hydrology of its rivers, which form the lifeline of nearly two billion people in the region. While a good monsoon is essential for replenishing these river systems, malevolence of water-related disasters such as floods, landslides, storms, heat waves, wildfires, droughts, glacial lake outburst floods (GLOFs), is becoming more pronounced in this region under the exacerbating effects of climate change. For instance, in the last forty years or so more than 70% of the flood events in the region took place during the summer monsoon season. Against this backdrop, the HKH Monsoon Outlook 2025 serves as a preliminary frame of reference into the summer monsoon conditions likely to prevail in the region during June – September 2025, based on seasonal forecasts for South Asia at large. The seasonal estimates are collated from the APEC1 Climate Centre (APCC), Copernicus Climate Service (C3S), International Research Institute for Climate and Society (IRI), 31st Session of South Asian Climate Outlook Forum (SASCOF -31) and several national agencies for meteorological assessments. With the forecasters unanimously predicting oceanic and atmospheric phenomena that usually affect (read disrupt) monsoon patterns in South Asia – such as, the El Nino Southern Oscillation (ENSO), the Indian Ocean Dipole (IOD), and the Madden-Jullian Oscillation (MJO) activities – to be neutral and /or weak during JuneJuly-August 2025, the likelihood of summer monsoon precipitations is potent this year. However, based on the incidence of below-normal snow cover in the Northern Hemisphere, especially between January and March 2025, along with an estimated mean summer temperature anomaly in South Asia ranging from 0.5°C to 2°C above normal, they also predict high probability of above-normal precipitations for most of South Asia, including HKH swathes. Looking at this possibility, we surmise that the HKH region is likely to be exposed to intensifying risks of rain-induced hazards like flash floods, landslides, and GLOFs if precipitations are intense or prolonged.