El Niño 2024: NZ’s Warmer, Drier Winter & Global Extreme Heat Risks

The World Meteorological Organization (WMO) has issued its strongest warning to date, declaring a 95% probability that the current El Niño event will intensify over the coming months, bringing with it a heightened risk of extreme heat, drought and severe weather systems across the Pacific and beyond. The alert, confirmed by New Zealand’s National Institute of Water and Atmospheric Research (NIWA), marks a critical escalation in global climate forecasts, with scientists emphasizing that the phenomenon is now “virtually certain” to develop within the next three months.

The WMO’s assessment, published this week, underscores a shift from earlier projections, where El Niño’s likelihood was placed at 70% as recently as May. The rapid increase in confidence reflects both observational data and advanced climate modeling, which now indicate a near-certainty of the event’s onset by August 2026. “The transition to El Niño is now imminent,” the WMO stated in its latest update, adding that the event is expected to persist through at least the end of the year, with potential impacts extending into 2027.

For New Zealand, the implications are particularly stark. NIWA meteorologists have warned of a warmer and drier than average winter for much of the country’s southern regions, including Otago and Southland, where temperatures could exceed typical seasonal norms by 0.5°C to 1.5°C. The forecast aligns with broader regional trends: Australia’s Bureau of Meteorology has already flagged elevated fire risks in southeastern states, while Pacific Island nations face heightened concerns over cyclonic activity and freshwater shortages. “El Niño doesn’t just bring heat—it disrupts entire weather patterns,” said a WMO climate scientist, noting that the phenomenon often amplifies existing vulnerabilities, such as drought in Southeast Asia and flooding in parts of South America.

The global urgency was further emphasized by the United Nations, which this week urged governments to prepare for “unprecedented extreme heat events” linked to El Niño. A UN climate advisory panel highlighted that the current event could rival the 1997–98 and 2015–16 El Niños, both of which triggered severe food insecurity, mass displacement, and economic losses exceeding $3 trillion worldwide. “This represents not a distant threat,” the panel warned. “The window for mitigation is closing.”

While El Niño’s onset is now considered likely, its precise intensity remains uncertain. The WMO’s latest bulletin refrained from categorizing the event as “strong” or “very strong,” instead stressing that even a moderate El Niño could exacerbate climate change-driven trends. “We’re entering uncharted territory,” a NIWA climate modeler noted. “The baseline conditions—warmer oceans, altered atmospheric circulation—mean even a typical El Niño could have outsized effects.”

Governments in the Pacific region have begun mobilizing resources, with New Zealand’s Ministry of Civil Defence activating its National Emergency Management Plan to address potential water restrictions, wildfire risks, and agricultural losses. Meanwhile, the WMO has called for a global coordination effort, urging nations to align disaster preparedness strategies with updated climate projections. The next critical update from the WMO is scheduled for mid-July 2026, when further refinements to the forecast are expected.

The development comes as scientists also monitor the La Niña-Southern Oscillation (ENSO) cycle, which governs Pacific Ocean temperatures and atmospheric pressure shifts. The WMO’s technical report clarifies that El Niño’s arrival would mark the end of a prolonged La Niña phase—the longest on record since 1950—which had previously tempered global temperatures but also contributed to record-breaking rainfall in parts of East Africa and South America. The shift to El Niño, by contrast, is projected to accelerate warming trends, with 2026 now considered a top contender for the hottest year ever recorded, pending further data.

For now, the focus remains on immediate preparedness. The WMO’s warning serves as a reminder that El Niño’s impacts are not uniform: while some regions brace for drought, others—such as the U.S. Gulf Coast and parts of South America—could face unseasonable rainfall and flooding. The organization’s call for global action reflects a growing recognition that climate phenomena like El Niño are no longer isolated events but systemic risks requiring cross-border collaboration.