ENSO events are in part characterized by warm temperature anomalies in the central to eastern equatorial Pacific. The Jan 2023 global sea surface temperature anomalies (SSTA) are given in the first figure.
ENSO index NINO3
SSTA are available from Nov 1981 to Jan 2023 here.
|gives more information on the ENSO cycle
|ENSO section of the IRI maproom
|More data and data images useful for monitoring ENSO