The world is experiencing another El Niño episode. El Niño is a climate pattern of more than usual warming surface waters in the eastern Pacific Ocean. It is defined as a phenomenon in the equatorial Pacific Ocean (Niño 3.4 region) marked by a positive departure for five consecutive three-month running mean sea surface temperature (SST = 28°C) by +0.5°C.
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Reference
Equatorial Pacific Sea Surface Temperatures: NCEI