El Nino Watch

World sea surface temperature

The average sea surface temperature of the world ocean between 60° S and 60° N, updated daily (Climate Reanalyzer, NOAA OISST v2.1).

Indices

This is the average temperature of almost the whole ocean surface. It has risen over the decades with climate change, and El Nino adds a temporary boost on top, because the Pacific releases heat.

The chart compares the current year with past years and with the 1991-2020 average for each day.

How to read it

A line far above all past years means record ocean warmth. It is global context: it does not tell you about Samui directly.

Why it matters for Koh Samui

A warmer ocean overall is part of why NOAA moved to RONI. It also raises the background odds of marine heatwaves and coral bleaching in the Gulf of Thailand.

Sources

Related

ENSO status now

ONI (NOAA CPC)
+1.80 °C, JJA 2026 (previous +1.39 °C)
RONI (NOAA CPC)
+1.36 °C, JJA 2026
Nino 3.4 weekly (NOAA CPC / OISST)
+3.0 °C anomaly, week of 16 Sep 2026 (SST 29.6 °C)