ENSO situation summary
ENSO-neutral remains in place in the tropical Pacific, but El Niño will be officially declared very soon by Earth Sciences New Zealand. There is a 100% chance that El Niño will form during July-September, with a 100% chance that El Niño will continue during August-October. The upcoming El Niño is expected to be very strong, perhaps rivalling the strongest El Niños on record.
As of 14 June 2026, the 30-day NINO3.4 Index (in the central equatorial Pacific) was 1.18˚C, in the El Niño range. The 30-day relative Niño 3.4 Index (RONI) was 0.68˚C, just below the El Niño threshold and reflective of the central equatorial Pacific being warmer than the average of the global tropics.
The Southern Oscillation Index (SOI) was on the El Niño side of neutral during March-May 2026 (-0.4), while the May value was -1.4 (i.e. in the El Niño range).
Subsurface ocean temperatures in the equatorial Pacific continue to be above average or well above average essentially everywhere across the basin, and upper-ocean heat content anomalies are well above average in the tropical eastern Pacific.
Particularly warm water is located in the eastern and central equatorial Pacific between depths of about 50-150 metres, where temperature anomalies of 5-7°C are widespread. This indicates that a very strong El Niño is on the brink of occurring.
During July-September, model guidance favours a continued chance of above normal or well above normal rainfall across most of Micronesia, island groups along the equator, southern French Polynesia, and Pitcairn Islands. This may result in enhanced rainfall for island groups such as Guam, the Northern Marianas, Federated States of Micronesia, the Marshall Islands, Nauru, and most of Kiribati.
Conversely, drier than normal or much drier than normal conditions are likely to occur for many island groups farther south, including Palau, Papua New Guinea southeast to Vanuatu, and from Fiji east to the Marquesas (see pages 6-7 for more information).