How El Niño Affects Southeast Asia: Drought, Haze, and Water Scarcity
Published: July 7, 2026 · 8 min read
TL;DR — El Niño Dries Out Southeast Asia
As El Niño shifts Pacific convection eastward, Southeast Asia gets stuck under sinking air — suppressing rainfall, drying out peatlands, and setting the stage for catastrophic fires. The 1997-98 event triggered Indonesian fires that burned 4.5-6M hectares, blanketed the region in haze for months, and cost $4.5B. Rice production in Thailand and Vietnam falls during strong events, pushing up global prices.
Why Southeast Asia Dries Out
During normal conditions, the warmest water in the Pacific sits around Indonesia — the "Maritime Continent." That warm pool drives intense convection, feeding the rainfall that sustains Southeast Asia's rainforests, rice paddies, and water supplies. El Niño slides that warm pool thousands of kilometers east. The convection follows. Indonesia, the Philippines, Thailand, and Vietnam are left underneath the sinking branch of the Walker Circulation — and sinking air kills rain.
The mechanism is the same one that dries out Australia during El Niño. In fact, Southeast Asia and Australia are on the same side of the ENSO see-saw — both get drier, both face elevated fire risk. But Southeast Asia has a particular vulnerability that Australia doesn't: vast areas of tropical peatland that become tinderboxes when dried out.
Peatland Fires and Transboundary Haze
Indonesia has about 22 million hectares of tropical peatlands — carbon-rich, waterlogged soils that have accumulated over thousands of years. When El Niño dries them out, they burn. And once peat fires start, they're nearly impossible to put out — they smolder underground for months, releasing massive amounts of smoke and carbon.
The 1997-98 El Niño triggered the worst peatland fire season in recorded history. An estimated 4.5-6 million hectares burned across Indonesia, mostly in Kalimantan and Sumatra. The smoke blanketed Southeast Asia for months — schools closed in Singapore and Malaysia, hundreds of thousands of people sought treatment for respiratory problems, and the economic damage was estimated at $4.5 billion. The 2015-16 event was nearly as bad: 2.6 million hectares burned, and the daily carbon emissions briefly exceeded those of the entire US economy.
| Event | Rainfall Deficit | Area Burned | Rice Production | Economic Cost |
|---|---|---|---|---|
| 1982–83 | -30% (Indonesia) | ~3.5M ha | -10% (SE Asia) | $1.2B+ |
| 1997–98 | -40% (Indonesia) | 4.5-6M ha | -8% (regional) | $4.5B |
| 2015–16 | -25% (Indonesia/Thai) | 2.6M ha | -5% (Thailand/Vietnam) | $16B (incl. health) |
| 2023–24 | -15% (late onset) | ~1M ha | Moderate impact | Limited |
Rice and Food Security
Thailand and Vietnam are the world's #1 and #3 rice exporters. Both depend on reservoir and river systems that are sensitive to El Niño rainfall deficits. The Mekong Delta, Vietnam's rice bowl, faces reduced dry-season flows during El Niño — less water for irrigation, saltwater intrusion pushing further inland, and reduced planted area. In Thailand, the central plains rice-growing region depends on reservoirs like Bhumibol and Sirikit, which see reduced inflows during El Niño dry spells.
The 2015-16 El Niño saw Thai rice production drop about 15%, and Vietnam's Mekong Delta experienced its worst drought and saltwater intrusion in 90 years. When Southeast Asia's rice exporters reduce output simultaneously, global rice prices move — and rice feeds 3.5 billion people.
Water and Hydropower
Southeast Asia's growing hydropower capacity — dams on the Mekong, dams across Indonesia and the Philippines — is vulnerable to El Niño drought. Reduced rainfall means reduced reservoir inflows and reduced power generation. During strong El Niño events, some hydropower plants in the region operate at 50-60% of capacity, forcing countries to fall back on expensive fossil fuel imports.
2026-2027 Outlook
WMO seasonal forecasts for late 2026 show elevated drought risk across the Maritime Continent, with below-normal rainfall expected from Indonesia through the Philippines to mainland Southeast Asia. The positive Indian Ocean Dipole developing alongside El Niño could partially offset the drying for western Indonesia, but models are inconsistent on this. Fire agencies across the region are prepositioning resources based on 2015-caliber fire scenarios — the conservative planning assumption for a very strong El Niño.
Economic & Agricultural Impacts in Southeast Asia
El Niño doesn't just change the weather — it reshapes entire economies. In Southeast Asia, the agricultural sector is often the first to feel the impact. When rainfall patterns shift, crop yields follow. When temperatures spike, livestock suffer. The ripple effects move through supply chains, commodity prices, and eventually household budgets.
For 2026-2027, key economic vulnerabilities include:
- Agriculture: Reduced rainfall during critical growing seasons can cut crop yields 10-30%. Farmers face difficult decisions about planting windows and crop selection.
- Water resources: Reservoir levels and groundwater recharge rates decline during El Niño droughts, affecting both irrigation and municipal water supplies.
- Energy demand: Higher temperatures drive up cooling demand. In regions dependent on hydropower, reduced rainfall creates a double squeeze — more demand, less supply.
- Insurance & disaster costs: El Niño-correlated extreme events (drought, flood, fire) increase claims and strain public disaster budgets.
The World Bank estimates that a strong El Niño can reduce GDP growth in vulnerable regions by 0.5-2.5 percentage points, primarily through agricultural losses and disaster response costs. For Southeast Asia, preparedness investments made now — drought-resistant crops, water storage, early warning systems — pay for themselves many times over during the event.
Explore more at the El Niño Guide — comprehensive climate science explained.