A rapidly intensifying El Niño has reached record atmospheric strength, increasing the likelihood of stronger winds, sharp temperature fluctuations and significant shifts in rainfall patterns across New Zealand in the months ahead.
According to the latest Seasonal Climate Outlook issued by Earth Sciences New Zealand, there is a 90% chance the weather phenomenon will reach or exceed very strong intensity between August and October, with peak conditions expected during the 2026–27 summer.
Previously nicknamed “Godzilla” by climate experts, the developing El Niño is forecast to become one of the strongest on record. International climate scientists have warned that the event could intensify extreme weather globally as it combines with long-term warming driven by fossil fuel emissions, Stuff has reported.
According to Stuff, the United Nations has described the situation as an “urgent climate warning”, while meteorologists say the event could rival or even surpass the powerful 1997 El Niño, which contributed to devastating heatwaves, floods, droughts, wildfires and other extreme weather events around the world.
Although the climate pattern is still developing, atmospheric observations recorded during July have already reached unprecedented levels.
In New Zealand, forecasters expect the effects to become more noticeable during spring as prevailing westerly winds strengthen. This is likely to bring more active weather systems, greater temperature variability and an increased risk of unusually strong winds, as reported by Stuff.
Seasonal temperatures from August to October are forecast to remain near or above average across most parts of the country, although occasional late-winter cold outbreaks are still expected during early August. Marine heatwave conditions also continue in coastal waters around much of the South Island and the Tasman Sea, Stuff has reported.
Rainfall patterns are expected to shift significantly. Wetter-than-normal conditions are forecast for the West Coast, Southern Alps, inland Otago and Southland, while much of the North Island is expected to experience below-average rainfall.
Northern regions, including Northland, Auckland, Waikato and Bay of Plenty, have a 50% chance of below-normal rainfall, with temperatures likely to remain near or above average.
Across the Central North Island, Taranaki, Whanganui, Manawatū and Wellington, temperatures are expected to be above or near average, while rainfall is forecast to be near or below normal, as reported by Stuff.
Gisborne, Hawke's Bay and Wairarapa are also expected to receive below-normal to near-normal rainfall, with soil moisture and river flows likely to remain at or below seasonal averages.
In Tasman, Nelson, Marlborough and Buller, forecasters expect greater temperature swings and windy conditions during spring, with rainfall also leaning towards below-normal levels.
According to Stuff, the West Coast, Southern Alps, inland Otago and Southland remain the only regions where above-normal rainfall is considered most likely, driven by stronger westerly weather systems.
Meanwhile, Canterbury and east Otago are forecast to experience warmer-than-average conditions, accompanied by increased temperature variability and generally below-normal rainfall.
Climate experts say the strengthening El Niño will continue to shape New Zealand's weather over the coming months, increasing the potential for more frequent extreme weather events and challenging seasonal conditions across different parts of the country, as reported by Stuff.