While the world debates the winter forecast, Peru has already endured deadly flooding and a fatal flood-rescue helicopter crash. A look at what's measured, not modeled, on the coastline where El Niño gets its name.
Every explainer on this site, including our own, eventually gets to a map of the Pacific with Peru circled and a caption like "El Niño's birthplace." It's true, and it's also easy to skate past as background trivia while everyone argues about winter forecasts. Peru's version of this event, known specifically as El Niño Costero, arrived first, and it's already done measurable damage. This is what's actually happened there so far, separate from the basin-wide probability numbers dominating this week's headlines.
Quick distinction worth keeping straight: El Niño Costero is a regional warming of the ocean off Peru and Ecuador. It can occur together with the basin-wide Niño 3.4 reading NOAA's CPC tracks for the official ENSO Advisory, but it can also develop on a different timetable, or without a corresponding basin-wide event at all. In 2026, Peru's coastal warming and its impacts emerged before CPC declared the basin-wide El Niño Advisory in June, and the two are now occurring alongside each other.
Death toll figures for the broader October 2025 through February 2026 window vary depending on source and tally date, some secondary reports put the fuller nationwide total higher, covering a wider time period and geography. We're anchoring the number above to the specific, wire-sourced figure (AFP/AP via Al Jazeera) for the Ica/Arequipa flooding and helicopter crash, rather than a rounder but less directly attributable total.
Peru is normally the world's largest fishmeal producer, and its anchovy fishery is a major input to global animal feed and aquaculture supply chains, though its exact share of global supply varies season to season with landings. The June 11 suspension in the northern-central zone isn't a forecast of future disruption, it's a government agency responding to assessments that have already come back showing heightened stock vulnerability. This is the same commodity thread we flagged as one to watch back on July 3, now with a concrete regulatory action attached to it.
NASA climate researcher Severine Fournier, speaking to NPR in mid-June, described strengthening westerly winds pushing more warm water from the western Pacific along the equator toward the Peruvian coast, and called Peru "ground zero" for El Niño for exactly that reason. In more technical terms, CPC's July 9 discussion describes the basin-wide mechanism as westerly wind anomalies over the western and central equatorial Pacific working alongside a downwelling Kelvin wave that deepened the eastern Pacific thermocline and raised temperatures near South America, the same general wind-and-wave pattern Fournier was describing in lay terms for the Peru-specific coastal warming.
At the time of that mid-June interview, NOAA's stated probability was 63% for a "very strong" El Niño arriving November through January. By CPC's July 9 discussion, that number had climbed to 81%. The forecast has been trending in one direction for a month; Peru's coast has been feeling a version of it the whole time.
Peru's ENFEN scientific committee, the official multi-agency body that tracks El Niño Costero, has elevated its forecast to "strong" and warned the anomalous warming off Peru and Ecuador will persist in the coming months, with continued risk of intensified rain, fishery disruption, and flooding. For the 2026-27 summer specifically, ENFEN puts a 48% probability on the event reaching "strong" magnitude and a 46% probability on "moderate," with effects potentially extending into 2027. Some of the large-scale ocean conditions associated with elevated regional rainfall risk remain present or are forecast to strengthen, though that doesn't mean a repeat of February's specific weather pattern, flood severity also depends on atmospheric circulation, moisture transport, and local ground conditions that a seasonal outlook doesn't resolve.