ENSOblog_Nino3.4_SSTA_time_series_20210519_large.png

Monthly sea surface temperature anomalies in the Niño 3.4 region of the tropical Pacific for (top) all first-year El Niño and (bottom) first-year La Niña winters since 1950, starting in the March before the first-year peak. Climate.gov graph based on ERSSTv5 temperature data.