Investigate warm months against their own season

Try this

Select a decade, then brush positive anomalies in the histogram; the line should narrow to the same months.
Alt-click a point and subtract its climatology from its Celsius temperature.
Clear the decade selection without clearing the anomaly brush and compare the broader population.

Limits

These are monthly temperatures for Niño 1+2, not a global ocean average or a Niño 3.4 event classification. The baseline is the 1981–2010 calendar-month mean; no modern data revision is substituted.