Source: Earth Sciences New Zealand
Earth Sciences New Zealand’s Seasonal Climate Outlook for February to April 2026 is attached.
Highlights:
- Weak La Niña conditions persist in the tropical Pacific but are on a weakening trend.
- The traditional Southern Oscillation Index (SOI) was on the La Niña side of neutral in January 2026.
- The Equatorial SOI (measuring the difference in atmospheric pressure between the eastern Pacific and Indonesia between 5oN and 5oS) was in the neutral range in January 2026 and convection and trade wind anomalies continued to reflect weak La Niña conditions.
- The Relative Oceanic Niño Index (RONI) continued to weaken in January 2026.
- This weakening of La Niña conditions is expected to accelerate in the coming months, with about an 80% chance for ENSO-neutral (El Niño – Southern Oscillation) conditions to return by the end of the forecast period.
- For the next three month period as a whole, the atmospheric circulation pattern over New Zealand is expected to see anomalous high pressure to the south of the country, and anomalous low pressure just to the north, leading to an easterly quarter flow anomaly overall.
- Slow-moving high pressure systems early in February should bring periods of traditional summer conditions to many parts of the country, interrupted by some shorter unsettled spells.
- From about mid-February, the risk of tropical incursions may increase again. Further settled conditions may occur in the remainder of March, but overall rainfall anomalies could be heavily skewed if a single significant event occurs. A dramatic pattern change is not anticipated in April, with rainfall events most likely to come from the north, contrasting with high pressure systems still bringing periods of settled conditions.
LiveNews: https://enz.mil-osi.com/2026/02/04/climate-news-earth-sciences-new-zealand-seasonal-climate-outlook-february-to-april-2026/