![](/sites/default/files/OceanicNinoIndex1950-2010.jpg)
Image caption
Graph showing the Oceanic Niño Index (difference from average sea surface temperatures in a key region of the tropical Pacific Ocean) from 1980-2012. Cooling La Niña events (blue shading) in the past decade have outnumbered warming El Niño events (red shading). Data courtesy of the NOAA Climate Prediction Center.