United Nations agencies warn that a strong El Niño is likely to form by late summer 2026, increasing risks of global extreme weather.

This climate pattern alters atmospheric circulation by raising Pacific sea-surface temperatures. Such shifts can trigger devastating droughts, floods, and heatwaves that disrupt food security and infrastructure on a global scale.

The World Meteorological Organization said there is an 80% chance [1] of the warming phenomenon developing between June and August 2026 [4]. Other projections from the National Oceanic and Atmospheric Administration (NOAA) and global agencies indicate a probability of over 90% [2] for a strong El Niño by late 2026 that persists through winter 2027 [2].

UN Secretary-General António Guterres said the current trajectory suggests a severe event. "The impacts will be greater, they will reach further, and they will cross borders at a devastating speed," Guterres said [3]. Some reports suggest the event could be the strongest warming phenomenon in the last two decades [5].

While some estimates place the chance of a strong or very strong El Niño by winter 2026-2027 at two out of three [6], the consensus among major agencies points toward a high-impact event. The timing of the arrival varies slightly among monitors, with some suggesting it could arrive early this summer [5] and others projecting development through August [1].

These conditions typically lead to erratic precipitation patterns. In some regions, this results in catastrophic flooding, while other areas face prolonged droughts that threaten agricultural yields. The UN and NOAA continue to monitor Pacific temperatures to refine these forecasts as the summer progresses.

“The impacts will be greater, they will reach further, and they will cross borders at a devastating speed.”

The convergence of high-probability forecasts from the WMO and NOAA suggests that the 2026-2027 cycle will be characterized by significant climatic instability. Because El Niño affects global jet streams, the resulting weather extremes often lead to simultaneous crop failures in different hemispheres, which can spike global food prices and strain international humanitarian aid resources.