South Asia Braces for Weaker Monsoon in 2026 as El Niño Threat Looms, WMO Warns

At the same time, temperatures — both daytime highs and nighttime lows — are projected to remain above normal, compounding risks of heat stress and water scarcity.

South Asia could face below-normal rainfall during the crucial June–September 2026 southwest monsoon season, raising concerns for agriculture, water security, and public health across one of the world's most climate-sensitive regions, according to a new seasonal outlook backed by the World Meteorological Organization (WMO).

The forecast, released by the South Asian Climate Outlook Forum, indicates the strongest likelihood of rainfall deficits across central parts of the region, while only limited pockets in the northwest, northeast, and southern areas are expected to receive normal to above-normal precipitation during the broader May–September monsoon period.

At the same time, temperatures — both daytime highs and nighttime lows — are projected to remain above normal, compounding risks of heat stress and water scarcity.

El Niño Emergence Signals Elevated Risk

The outlook is driven by evolving global climate patterns, with meteorological experts pointing to a high probability of El Niño conditions developing during the 2026 monsoon season. El Niño events are historically associated with weaker monsoons and reduced rainfall across South Asia.

In parallel, the Indian Ocean Dipole (IOD) is expected to shift from a neutral to a positive phase, another factor that can influence rainfall distribution and variability in the region.

While forecasters caution that predictions made during the spring "predictability barrier" carry some uncertainty, there is strong consensus among regional experts about the overall trend toward drier conditions.

A Lifeline Under Pressure

The southwest monsoon is the backbone of South Asia's economy and ecology, delivering 75% to 90% of annual rainfall in most countries, including India, Pakistan, Bangladesh, and Nepal. It replenishes rivers, groundwater, and reservoirs that sustain agriculture, drinking water supplies, and hydropower generation.

A weaker monsoon could have far-reaching consequences:

• Agriculture: Reduced rainfall threatens crop yields, particularly for rain-fed farming systems

• Food security: Vulnerable populations may face increased risk of shortages and price volatility

• Water resources: Lower recharge of rivers and aquifers could strain urban and rural supply

• Energy: Hydropower output may decline, affecting electricity availability

At the same time, uneven rainfall patterns could still trigger localized flooding, a common feature of monsoon variability that continues to cause loss of life and infrastructure damage each year.

Planning and Preparedness Key

Seasonal forecasts such as this play a critical role in enabling governments, farmers, and industries to prepare in advance. The information supports decision-making in:

• Agricultural planning, including crop selection and irrigation strategies

• Disaster risk management, especially for droughts and floods

• Public health, through heat action plans and disease preparedness

• Energy planning, particularly for hydropower and renewable systems

"These outlooks are essential tools for protecting lives and livelihoods," the WMO noted, highlighting their growing economic value globally.

Regional Collaboration Strengthens Forecasting

The forecast was developed through collaboration among nine National Meteorological and Hydrological Services in South Asia — Afghanistan, Bangladesh, Bhutan, India, Maldives, Myanmar, Nepal, Pakistan, and Sri Lanka — demonstrating the importance of regional data-sharing and scientific cooperation.

National agencies are expected to issue country-specific updates in the coming weeks and months to refine the outlook and guide local decision-making.

WMO Expands Early Warning Systems

In response to increasing climate variability, the WMO is scaling up efforts to strengthen multi-hazard early warning systems across South Asia. These include:

• Flash flood forecasting tools

• Drought monitoring and water management systems

• Climate-informed public health strategies

A key initiative is the newly established South Asia Heat and Health Hub, developed in partnership with the World Health Organization (WHO), which aims to coordinate responses to rising heat-related risks.

Additionally, the South Asia Climate–Health Desk is enhancing collaboration between meteorological and health authorities, helping integrate climate data into public health planning.

Global Coordination for Rapid Response

The WMO's Coordination Mechanism continues to provide regular global updates, including weekly hydrometeorological scans and seasonal outlook briefings, which are shared with UN agencies and humanitarian organizations to support early action.

With the potential emergence of El Niño adding urgency, these tools are expected to play a vital role in mitigating the impacts of a weaker monsoon.

A Critical Season Ahead

As South Asia approaches the 2026 monsoon season, the forecast serves as an early warning of heightened climate risks. For a region where millions depend directly on seasonal rains, even modest deviations can have profound economic and humanitarian consequences.

The coming months will test preparedness systems, policy responses, and regional cooperation — as governments and communities work to navigate the uncertainties of an increasingly variable climate.