This video shows daily sea surface temperature anomalies (difference from normal) throughout 2010. Places that were warmer than the long-term average (1980-2010) are shades of red, places that were cooler than average are blue, and places where temperatures were near average are white.
When 2010 began, temperatures in the tropical eastern Pacific were warmer than average (red), an indication that El Niño, the warm phase of a naturally occurring climate pattern known as the El Niño-Southern Oscillation (ENSO), was underway.
By late spring, conditions were neutral, but the Pacific quickly switched to the cool phase of the ENSO pattern in summer. By July, La Niña was in place, and by the end of 2010, it had intensified into a moderate-to-strong event.
View this video on YouTube: https://www.youtube.com/watch?v=eYi56r9AmEc&feature=youtu.be
Animation by Ned Gardiner. Maps by Dan Pisut, NOAA Environmental Visualization Lab, based on NOAA sea surface temperature data.