The Climate Prediction Center defines El Niño conditions as existing when a one-month positive sea surface temperature anomaly of 0.5C or greater is observed in the Niño-3.4 region of the equatorial Pacific Ocean, an expectation that the 3-month Oceanic Niño Index (ONI) threshold will be met (see graphs below), and an atmospheric response typically associated with El Niño is observed over the equatorial Pacific Ocean. Please visit the Climate Prediction Center website for El Niño status and predictions.
El Niño/Southern Oscillation (ENSO) DIAGNOSTIC Discussion
El Niño/ENSO: Recent Evolution, Current Status and Predictions
Southern California Coastal Ocean Observing System El Niño page
Monthly reports of recent climate conditions provided by Southwest Fisheries Science Center. Please contact Jerrold Norton (Jerrold.G.Norton at noaa.gov) for more information.
Download Reports
The NOAA 1/4° daily Optimum Interpolation Sea Surface Temperature data (https://www.ncdc.noaa.gov/oisst).