Unprecedented El Niño Could Trigger Extreme Weather in New Zealand
Earth Sciences New Zealand (ESNZ) warns that an “unprecedented” El Niño event may develop this year, with conditions in the tropical Pacific Ocean resembling one of the strongest on record, according to chief weather scientist Chris Brandolino.
What’s Driving the Concern?
Ocean temperatures in the central Pacific have shifted dramatically, rising from 1°C below average in January to 0.7°C above average, a “remarkable about-face” that has bypassed neutral phases typically seen in the climate cycle, Brandolino said. This rapid transition from La Niña to El Niño within six months is “quite remarkable,” he added.

El Niño forms when warmer-than-usual temperatures in the eastern and central Pacific weaken trade winds, shifting rainfall patterns. This could lead to drier conditions in eastern and northeastern New Zealand, increasing risks of drought and wildfires, though impacts are not guaranteed, Brandolino noted.
How Does This Compare to Past Events?
The five strongest El Niño events on record occurred in 1972/73, 1982/83, 1992/93, 1997/98, and 2015/16. Current models suggest this event could rival those, with ocean temperature anomalies potentially exceeding 3°C above average. A “Super El Niño” is defined as anomalies reaching or surpassing 2°C, a threshold this event is forecast to comfortably exceed, Brandolino said.
Australia’s Bureau of Meteorology, the Japan Meteorological Agency, and the U.S. National Ocean and Atmospheric Administration (NOAA) have already declared El Niño conditions, though ESNZ is awaiting formal confirmation.
Regional Impacts: Who’s Most at Risk?
Canterbury, already in meteorological drought, faces heightened risks, with Brandolino warning, “They’re already on the back foot.” The eastern South Island, lacking the moisture reserves of the upper and eastern North Island, is particularly vulnerable to prolonged dryness.

Areas that received heavy rain during La Niña, such as the upper North Island, may see a rapid shift to dry conditions. However, higher ground moisture in the eastern North Island could delay impacts there, according to the scientist.
Why This Matters: Lessons from the Past
Historical data shows El Niño events can lead to severe consequences. The 1997/98 event, for example, caused widespread droughts and wildfires globally. While New Zealand’s geography and local weather patterns may temper some effects, the current forecast suggests a “distinctly possible” scenario of “unprecedented” strength, according to Brandolino.
Climate agencies use slightly different criteria to declare El Niño, but all rely on shared data. ESNZ is closely monitoring conditions to determine if it will formally categorize the event in the coming weeks.
Did You Know?
The term “Super El Niño” refers to ocean temperature anomalies exceeding 2°C. The 2015/16 event, one of the strongest on record, caused $30 billion in global damages, according to the World Meteorological Organization.
Pro Tip: How to Prepare
Residents in drought-prone areas should monitor weather updates from ESNZ and local authorities. Farmers and water managers are advised to assess resource allocation strategies ahead of potential dry spells.

FAQ: Answers to Common Questions
What is El Niño?
El Niño is a climate phenomenon characterized by unusually warm ocean temperatures in the central and eastern Pacific, which disrupts global weather patterns.
How does it affect New Zealand?
El Niño typically brings drier, windier conditions to eastern and northeastern New Zealand, increasing drought and wildfire risks, while southwestern regions may see wetter weather.
Why is this event different?
This El Niño is forecast to exceed 2°C anomalies, potentially rivaling the strongest on record. Its rapid development from La Niña also sets it apart from historical trends.
Stay Informed: What’s Next?
ESNZ will provide updates as conditions evolve. For daily weather insights, subscribe to Ngā Pitopito Kōrero, a curated newsletter from Radio New Zealand.














