ENSO situation summary
El Niño has now been officially declared, and it is strengthening rapidly in the tropical Pacific Ocean. There is a 100% chance that El Niño will continue during August-October, and a 100% chance that El Niño will continue through the rest of 2026. This El Niño is expected to be one of the strongest El Niños on record, if not the strongest.
As of 12 July 2026, the 30-day NINO3.4 Index (in the central equatorial Pacific) was 1.82˚C, well into El Niño range. The 30-day relative Niño 3.4 Index (RONI) was 1.27˚C, in El Niño range and reflective of the central equatorial Pacific being warmer than the average of the global tropics.
The Southern Oscillation Index (SOI) was well into El Niño range during April-June 2026 (-1.5), while the June value was -2.3 (strong El Niño range).
Subsurface ocean temperatures in the equatorial Pacific continue to be above average or well above average everywhere across the basin, and upper-ocean heat content anomalies are well above average in the tropical eastern Pacific.
Extremely warm water is located in the eastern equatorial Pacific between depths of about 50-100 metres, where temperature anomalies of 5-7°C are widespread. This indicates that a strong El Niño is now occurring, and further strengthening is expected in the coming months.
During August-October, model guidance favours above normal or well above normal rainfall across eastern Micronesia and island groups along the equator. This may result in enhanced rainfall for island groups such as Federated States of Micronesia, the Marshall Islands, Nauru, and most of Kiribati, Tuvalu, and Tokelau.
Conversely, drier than normal or much drier than normal conditions are likely to occur for many island groups in a large arc from Palau and Papua New Guinea southeast to Vanuatu and New Caledonia, and from Fiji east to the Marquesas. Many of these island groups will also have a high chance to be extremely dry during August-October (i.e. to receive less than 25% of their normal rainfall). See pages 6-7 for more information.
