Rough sea forecast (TMD): speedboats, snorkel and island trips may be cancelled; car ferries usually run but can be delayed. This is not an operator cancellation.
Koh Samui weather warnings & sea conditions today
Sunday 15 November · As of 02:32 ICT (Samui time, UTC+7) · last update 21:10
Here you find weather warnings and sea-condition notices that matter on Koh Samui: heavy rain, strong wind, high waves and small-boat warnings for the lower Gulf of Thailand. We take warnings from official sources first, mainly the Thai Meteorological Department, and say clearly when a notice is a forecast rather than an observation. Every item shows its source, when it was issued and until when it applies, and it disappears automatically after that time. During the northeast monsoon (roughly November to January) boat trips and ferries can be cancelled at short notice; the operator always has the final word. For month-by-month climate averages and what to pack, see our weather guide.
Right now
Yesterday
Official forecast
TMD forecast for the southern Gulf coast
30° / 23°C
- Scattered thundershowers and isolated heavy rain in Chumphon, Surat Thani, Nakhon Si Thammarat, Phatthalung, Songkhla, Pattani, Yala and Narathiwat.
- Minimum temperature 21-25 °C. Maximum temperature 30-34 °C.
Whole southern east coast
Ended in the last 14 days
Yesterday
Rough sea forecast (TMD): speedboats, snorkel and island trips may be cancelled; car ferries usually run but can be delayed. This is not an operator cancellation.
13 Nov 2026
Rough sea forecast (TMD): speedboats, snorkel and island trips may be cancelled; car ferries usually run but can be delayed. This is not an operator cancellation.
Rough sea forecast (TMD): speedboats, snorkel and island trips may be cancelled; car ferries usually run but can be delayed. This is not an operator cancellation.
On 13 November 2026, isolated heavy rains to very heavy rain are forecast in the South especially in Prachuap Khiri Khan, Chumphon and Surat Thani Province. People in the South should beware of heavy to very heavy rain and accumulation that may cause flash floods, overflows and…
The rather strong high-pressure system from China covering upper Thailand and the South China Sea is weakening while the moderate northeast monsoon prevails over the Gulf and the South. Isolated heavy to very heavy rains are forecast in the South especially in Prachuap Khiri Kha…
Rough sea forecast (TMD): speedboats, snorkel and island trips may be cancelled; car ferries usually run but can be delayed. This is not an operator cancellation.
12 Nov 2026
Rough sea forecast (TMD): speedboats, snorkel and island trips may be cancelled; car ferries usually run but can be delayed. This is not an operator cancellation.
The rather strong high-pressure system from China extend to upper Thailand and the South China Sea while the westerly trough will move pass Myanmar, the North of Thailand, and upper Laos. The moderate northeast monsoon prevails over the Gulf, the South and the Andaman Sea. Cool…
Rough sea forecast (TMD): speedboats, snorkel and island trips may be cancelled; car ferries usually run but can be delayed. This is not an operator cancellation.
The rather strong high-pressure system from China extend to upper Thailand and the South China Sea while the westerly trough will move pass Myanmar, the North of Thailand, and upper Laos. The moderate northeast monsoon prevails over the Gulf, the South and the Andaman Sea. Cool…
Rough sea forecast (TMD): speedboats, snorkel and island trips may be cancelled; car ferries usually run but can be delayed. This is not an operator cancellation.
Rough sea forecast (TMD): speedboats, snorkel and island trips may be cancelled; car ferries usually run but can be delayed. This is not an operator cancellation.
11 Nov 2026
The rather strong high-pressure system from China extend to upper Thailand and the South China Sea while the westerly trough will move pass Myanmar and the North. The moderate northeast monsoon prevails over the Gulf, the South and the Andaman Sea. Cool in the morning with stron…
Rough sea forecast (TMD): speedboats, snorkel and island trips may be cancelled; car ferries usually run but can be delayed. This is not an operator cancellation.
Rough sea forecast (TMD): speedboats, snorkel and island trips may be cancelled; car ferries usually run but can be delayed. This is not an operator cancellation.
Another rather strong high-pressure system from China extend to upper Thailand and the South China Sea while the westerly trough will move pass Myanmar and the North. The moderate northeast monsoon prevails over the Gulf, the South and the Andaman Sea. Cool in the morning with s…
Rough sea forecast (TMD): speedboats, snorkel and island trips may be cancelled; car ferries usually run but can be delayed. This is not an operator cancellation.
Rough sea forecast (TMD): speedboats, snorkel and island trips may be cancelled; car ferries usually run but can be delayed. This is not an operator cancellation.
The another rather strong high-pressure system from China extend to upper Thailand and the South China Sea while the westerly trough will move pass Myanmar and the North. The moderate northeast monsoon prevail over the Gulf, the South and the Andaman Sea. Cool in the morning wit…