The tropical Pacific is transitioning from weak La Niña conditions toward ENSO-neutral, with El Niño probability rising to 40% by May–July 2026. This shift will disrupt global precipitation and temperature patterns, creating acute risks to agricultural productivity, food affordability, and disaster exposure across vulnerable regions. The transition window presents a critical period of elevated uncertainty and compounding climate stress.
What the evidence shows
Key passages from the source
Stacked probability chart showing La Niña, ENSO-neutral, and El Niño probabilities across March–May, April–June, and May–July 2026 forecast windows.
Human and systemic impacts
The ENSO transition poses acute mortality and affordability risks. El Niño onset typically intensifies extreme weather events—including tropical cyclones, droughts, and flooding—that directly kill people through infrastructure collapse and exposure, and indirectly through disease and malnutrition cascades. Agricultural disruption is the primary affordability vector: crop failures and yield volatility in staple-producing regions will drive food prices beyond reach for food-insecure populations, particularly in Sub-Saharan Africa, South Asia, and Central America. Coastal and agricultural communities face compounded displacement pressure as intensified storms and prolonged droughts force migration from affected regions simultaneously. The forecast uncertainty itself creates a secondary harm: farmers cannot reliably plan planting cycles, governments cannot pre-position disaster resources with confidence, and humanitarian systems cannot mobilize preventively. Vulnerable populations—those already living on subsistence agriculture or in informal settlements—bear disproportionate exposure because they lack adaptive capacity, financial buffers, and access to climate-informed early warning systems.
Broader significance
ENSO transitions are among the most predictable and consequential climate events on interannual timescales. A shift from La Niña to El Niño represents a fundamental reorganization of tropical Pacific ocean-atmosphere dynamics that cascades into global precipitation and temperature anomalies within months. The rising El Niño probability during May–July 2026 signals that the window for anticipatory adaptation—crop insurance activation, water storage, disaster preparedness, food reserve positioning—is narrowing. This briefing window is critical for policy and operational decision-making; delays in response will amplify human harm.