← El Niño & La Niña home · part of extremewx.org · What happens around the world in an El Niño or La Niña of a given strength, compared with the average year. Drag the slider right for El Niño, left for La Niña (the Dec–Feb, northern-winter value of NOAA's ocean index, RONI), pick a variable, or switch to the normal Climatology; choose the whole year, a season or a single month with the bar above the map. An ENSO year runs from June to May (1997–1998 = June 1997 – May 1998), the twelve months over which an event usually grows, peaks and decays. Hover over the map to read the values. More options are under Advanced settings. These maps describe past years, not a forecast: for NOAA’s official U.S. outlook for the coming months, see the CPC seasonal outlooks, and for the El Niño or La Niña under way now, CPC’s ENSO discussion. Send feedback with bugs or requests.