El Nino Watch
Preparedness checklist for a strong El Nino on Koh Samui: water storage, food, power cuts, heat, haze, floods and an exit plan, with quantities and local shops.
Samui has had shortages before (2016, and PWA rotating rationing from 3 August 2026). With El Nino, February-April 2027 is the riskiest period. (9 items)
If rough seas stop the ferries or the power goes out, the island's supermarkets empty fast. The Red Cross recommends 2 weeks of supplies at home. (6 items)
Monsoon storms and heatwaves (peak air-conditioning use) cause outages; the island has a limited power supply from the mainland. (6 items)
Heat, doubtful water and dengue (more mosquitoes with heat and rain). The island's hospitals can be overwhelmed or cut off from the mainland. (8 items)
El Nino likely makes the 2027 dry season (March-May) hotter; above 41 °C feels-like, heatstroke becomes a real risk. (4 items)
In El Nino years, fires in Indonesia and Malaysia can send haze as far as southern Thailand (2015, 2019). (3 items)
The northeast monsoon (October-December) brings Samui's heaviest rain, even during an El Nino. Pabuk (January 2019) hit the island. (8 items)
Cell towers go down when the power is out for a long time. (4 items)
Without power or network, cards and ATMs stop working. (2 items)
The island can only be left by ferry, catamaran or plane. When seas exceed 2 m, boats stop: leave early, not at the last minute. (5 items)
A rushed departure or a flood leaves no time to look for them. (5 items)
Preparing the house reduces damage; pets are not always accepted on boats or in shelters. (5 items)
Prepare -- strong El Nino (ONI +1.80 °C JJA 2026; RONI +1.36 °C; Nino 3.4 +3.0 °C week of 16 Sep). No immediate threat on Samui: rain 108% of normal (90 d to 19 Sep), waves max 0.6 m (forecast to Sun 27 Sep), no cyclone within 800 km (nearest 1,997 km). Watch: heavy rain / flood -- TMD heavy-rain bulletin 225/2569 for the South, in force to Sun 27 Sep (forecast 25 mm over 3 days). Next risk: NE-monsoon heavy rain and rough seas Oct-Dec 2026 (November wettest); water stress Feb-Apr 2027.