El Niño is now near certain to be very strong, with a meaningful chance of becoming the strongest event in the modern record. In its 13 August 2026 ENSO discussion, NOAA puts the chance of a very strong El Niño in fall and winter 2026–27 at more than 90 percent, with a 69 percent chance of an event exceeding every El Niño since 1950.

Ocean conditions are already exceptional: July’s Niño-3.4 index reached +1.4°C, and the eastern Pacific Niño-1+2 index reached +2.9°C, with subsurface temperature anomalies as high as +10°C. The World Meteorological Organization likewise expects seasonal sea-surface temperature anomalies above +2.9°C, reinforced by a positive Indian Ocean Dipole. For CVF-V20 members, the question is how to manage such an event that may have no analog in the instrumental record.

This updated science bulletin sets out what the latest observations and forecasts imply for member states, and what governments should do now to prepare for the possibility of an exceptionally severe event.