El Niño ‘Well Underway’: WMO Warns of 80% Chance by September, Extreme Heat Ahead

A Global Shift in Climate Patterns

El Niño, characterized by a periodic warming of sea surface temperatures in the central and eastern Pacific, is transitioning rapidly from neutral conditions. According to the WMO, this shift is likely to persist until November, with models currently debating whether the event will be moderate or strong. The agency has observed subsurface ocean temperatures exceeding 6C above average, creating a significant reservoir of heat that is currently driving surface warming across the Pacific. The implications for global weather are profound. As the World Meteorological Organisation reported, the pattern disrupts regional climates by increasing rainfall in parts of the southern United States, the Horn of Africa, and central Asia, while simultaneously triggering drought conditions in Indonesia, Australia, Central America, and parts of South Asia. “We need to prepare for a potentially strong El Nino event – which will exacerbate drought and heavy rainfall and increase the risk of heatwaves both on land and in the ocean,” Celeste Saulo, Secretary-General, World Meteorological Organisation

Impacts on New Zealand’s Winter and Beyond

For New Zealand, the arrival of El Niño marks a pivot away from the heavy rain events that defined the early part of the year. Earth Sciences New Zealand (ESNZ) indicates that the country’s weather patterns are shifting toward a west or southwesterly flow anomaly. While June may act as a transitional month, the seasonal outlook for the remainder of winter suggests a marked increase in active weather. Chris Brandolino, a principal forecasting scientist at ESNZ, emphasized that the signs of the upcoming cycle are clear. “All the makings for a rather profound and intense event are there as well.”Chris Brandolino, Principal Forecasting Scientist, Earth Sciences New Zealand The regional impacts within the country will be varied. Residents in the west of the South Island should brace for near-normal or above-normal rainfall. Conversely, the east of the South Island and the North Island are facing a higher probability of below-normal rainfall. This deficit is expected to create challenges for water-reliant sectors, as the lack of winter precipitation will likely translate to diminished groundwater recharge.

Economic and Food Security Risks

The return of El Niño arrives at a delicate moment for the global economy, which is already managing the inflationary pressures linked to the war in Iran. Experts warn that the weather pattern could jeopardize food supplies that remain under strain from climate breakdown and disrupted fertilizer flows. The Energy & Climate Intelligence Unit, a British thinktank, noted that the anticipated 2027 global temperature records will pose life-or-death risks for many farming communities. Cocoa production is already under scrutiny; Hein Schumacher, CEO of Barry Callebaut, reported that growing regions in Ecuador and West Africa—which account for 60 percent of global output—face potential yield reductions. “El Niño could have an effect that could lead to, you know, a few thousands per tonne.”Hein Schumacher, CEO, Barry Callebaut Currently, London cocoa futures are trading at US$3,964.10 per metric tonne. Industry leaders are monitoring the situation with extreme caution, as the combination of reduced harvests and climatic instability threatens to push vulnerable communities beyond their limits.

Preparing for the 2026-27 Austral Summer

The New Zealand Herald reports that peak El Niño conditions are projected to occur during the austral summer of 2026-27. For farmers and horticulturists, the current window is critical for planning. The combination of dry conditions, high winds, and elevated temperatures creates an environment prone to out-of-season fires. Otago Daily Times coverage notes that while parts of the South Island may experience a cold and wet winter, the broader national trend toward drier-than-usual conditions in the east is a significant concern for the coming growing season. As the ENSO signals strengthen over the coming months, authorities are urging citizens to stay informed through regular forecasts, noting that the “prospect of below normal winter rainfall in several regions is likely to translate to below-normal groundwater recharge.” The UN Secretary-General, António Guterres, has framed the situation as an urgent climate warning, stating that the conditions will “pour fuel on the fire of a warming world.” With the potential for significant impacts across borders, the focus remains on the necessity for immediate, proactive preparation.