The top panel shows the time series of the Oceanic Niño Index (ONI), which is the seasonal average of sea surface temperature anomalies in the Niño-3.4 region of the east-central equatorial Pacific Ocean. ONI values are also provided in this table and here. The bottom panel shows the Relative Oceanic Niño Index, which can be found here. Both indices show all three-month average (seasons) overlapping starting in December-February (DJF) 1949-50 to DJF 2020-21. Red shading shows El Niño episodes and blue shading shows La Niña episodes (thresholds must be exceeded for at least 5 consecutive, overlapping seasons). NOAA Climate.gov figure using data from NCEI ERSSTv5.