El Nino Watch
A period of days to months when the sea is unusually warm for the season. El Nino years often bring marine heatwaves to Southeast Asian seas.
Ocean
A marine heatwave is like a heatwave on land, but in the ocean: the sea surface stays much warmer than usual for the season for days to months.
Around Samui, a marine heatwave means coral bleaching risk, stressed fisheries, and warmer, more humid nights on land. Coral Reef Watch's DHW is the best single measure of its effect on reefs.
On the Map, the SST anomaly layer shows it as orange/red around the Gulf of Thailand.