Oceania
New Zealand El Niño 2026 outlook
Warmer than average
Seasonal outlook
October to December 2026
Likely warmer than usual
The European seasonal forecast model expects New Zealand to average about 0.3°C warmer than usual for this time of year.
Estimated chance of each outcome. With no forecast signal, each would be about 1 in 3.
Technical details
- Model: ECMWF SEAS5 (system 51) ensemble mean, from the Copernicus Climate Data Store.
- 2 m air temperature anomaly: +0.34°C, averaged over October to December 2026, relative to the model's 1993 to 2016 average.
- Taken at the model grid point nearest -40.90, 174.90, so it represents that area rather than the whole country.
- Chances (cooler / about usual / warmer): 29% / 30% / 41%. Estimated by Niño Tracker from the size of the anomaly, because the ensemble mean product does not include the model's own odds.
- Confidence is set by the anomaly's size: under 0.5°C low, 0.5 to 1°C moderate, 1°C or more high.
El Niño right now
Very strong El Niño
El Niño is a natural warming of the central and eastern tropical Pacific Ocean that shifts weather patterns around the world. Over July to September 2026, sea temperatures there averaged about 2.2°C above normal, which counts as a very strong event.
Technical details
- Oceanic Niño Index (ONI): +2.16 for JAS 2026. It is the 3-month average sea surface temperature anomaly in the Niño 3.4 region (5°N to 5°S, 120°W to 170°W), from NOAA.
- El Niño conditions are +0.5°C or more, La Niña −0.5°C or less, sustained for five overlapping 3-month seasons. Strength: weak 0.5 to 0.9, moderate 1.0 to 1.4, strong 1.5 to 1.9, very strong 2.0 or more.
- NOAA now uses a relative version of this index (RONI) for official monitoring. The ONI is still published each month.
- Last updated Oct 23, 2026, 12:00 AM UTC.
Upcoming 7 Days
Wellington
- This week avg
- 14.5°
- Last year avg
- 13.4°
than the same week last year, on average.
Daily average
Temperatures in °C. Tap or hover the chart to compare each day.
Across these 6 cities, it averaged 11.5°, 2.6° cooler than this week's forecast of 14.2°.
Niño Tracker updates weather data two times a day.
El Niño and New Zealand: common questions
How will El Niño affect New Zealand in 2026?
The European seasonal forecast model expects New Zealand to average about 0.3°C warmer than usual for this time of year. The forecast covers October to December 2026. Only a slight lean, so treat it as a rough guide.
How does El Niño usually affect New Zealand?
Typical effects of past El Niño events in New Zealand: more frequent westerlies; regional variability. Every event is different, so these are tendencies rather than guarantees.
How does La Niña affect New Zealand?
Typical effects of past La Niña events in New Zealand: warmer north, more northeasterly winds. La Niña often pushes weather roughly the opposite way to El Niño.
What is the weather forecast for New Zealand this week?
Over the next 7 days, forecast lows and highs are: Wellington 11 to 19°C, Auckland 11 to 22°C, Christchurch 7 to 28°C, Queenstown 3 to 23°C, Hamilton 6 to 22°C and Dunedin 4 to 23°C. Across these cities the average is 14.2°C. Last year the same week averaged 11.5°C, so this week is forecast to be 2.6°C warmer.
Is El Niño happening right now?
El Niño is a natural warming of the central and eastern tropical Pacific Ocean that shifts weather patterns around the world. Over July to September 2026, sea temperatures there averaged about 2.2°C above normal, which counts as a very strong event. El Niño continues to strengthen, with a strong-to-very strong El Niño likely through January-March 2027 (remaining greater than an 83% chance).