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Island Climate Update

A monthly summary of the climate in the tropical South Pacific islands, with an outlook for the coming months.

February-April 2026 Island Climate Update

Weak La Niña conditions currently remain in place in the tropical Pacific, but a return to ENSO-neutral is likely in the next 1-3 months. There is about an 80% chance that La Niña will dissipate to ENSO-neutral during February-April, with a 90% chance for ENSO-neutral during March-May.

As of 12 January 2026, the 30-day NINO3.4 Index (in the central equatorial Pacific) was -0.70˚C, near the La Niña range. The 30-day relative Niño 3.4 Index (RONI) was -1.04˚C, in the La Niña range and reflective of the central equatorial Pacific being cooler than the average of the
global tropics.

The Southern Oscillation Index (SOI) was on the La Niña side of the neutral range during October-December (+0.7), while the December value was -0.2 (Neutral).

Subsurface ocean temperatures in the equatorial Pacific remain above average in the western part of the basin with cooler than average temperatures in eastern areas. However, the above average temperatures in the western part of the basin have started rapidly moving into the central Pacific.

Cooler than average temperatures are currently located in the central and eastern equatorial Pacific to depths of about 50 metres. However, warmer than average temperatures below 50-100 metres are rapidly progressing into the central and eastern equatorial Pacific, signalling that La Niña is likely nearing its end.

During February-April, model guidance favours an enhancement in convective forcing over Micronesia, collocated with the warmest sea surface temperatures. This may lead to enhanced rainfall for island groups such as Palau, Guam, the Northern Marianas, Federated States of Micronesia, and the Marshall Islands.

Conversely, drier than normal conditions are likely to occur for most island groups near the equator, including Kiribati, Tuvalu, Tokelau, northern Cook Islands, and northern French Polynesia (see pages 6-7 for more information).

Tropical cyclone season in the southwest Pacific continues through April, and there are indications that one or more tropical cyclones may form over the next couple of weeks.

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Island Climate Update - February 2026 [PDF 5 MB]

Additional resources

Additional regional and country situation summary and forecast information can be obtained below. Current rainfall accumulation status and other derived summary information are updated on a daily basis (with a 2-day lag), with seasonal forecast information updated once per month.

About the Island Climate Update

NIWA is the Network co-lead for the WMO RA V Regional Climate Centre Node on Long Range Forecast and consortium member for nodes on Climate Monitoring, Operational Data Services and Training.

Development and production of the ICU is supported by NIWA Strategic Science Investment Funding under contract PRAS2301. The Island Climate Update bulletin and associated video and products are prepared as soon as possible at the start of each month. Delays in data availability occasionally arise. While every effort is made to verify the data, NIWA does not guarantee the accuracy and reliability of the analysis and forecast information presented and accepts no liability for any losses incurred through the use of this bulletin and its contents. The contents of this bulletin and all associated products produced by the Island Climate Update may be freely disseminated provided the source is acknowledged.

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