OCEAN · EL NIÑO / LA NIÑA

El Niño / La Niña

Whether the tropical Pacific is in an El Niño (warm), La Niña (cool) or Neutral phase right now — the biggest year-to-year swing in the ocean–climate system. A box over the Niño-3.4 region (5°N–5°S, 170°W–120°W) is tinted by the current phase and labelled with the live Oceanic Niño Index (ONI). El Niño (ONI ≥ +0.5°C) and La Niña (≤ −0.5°C) reshape rainfall, drought, hurricane seasons and fisheries for billions of people; the equatorial-Pacific stripe in the Sea Temp Anomaly layer is this same signal as a global field. Updated monthly from NOAA.