Weather and Tide Forecast for the Gulf of Thailand (Samui/Phangan/Tao/Surat Thani)

Gulf of Thailand Weather Forecast (Samui/Phangan/Tao/Surat Thani) 17 to 23 November, 2025.

17 Nov, Monday

Temp: 30°C / 21°C
Weather: Heavy rain, thunderstorms (40% area)
Wind: 17 km/h
Sailing: Caution advised; increasing winds, waves 1–2 m
Tide: Moderate tides

18 Nov, Tuesday

Temp: 29°C / 18°C
Weather: Heavy rain (30% area)
Wind: 19 km/h
Sailing: Rough conditions; strong wind-waves expected
Tide: Moderate to high tides

19 Nov, Wednesday

Temp: 27°C / 17°C
Weather: Rain (0% area indicated, but regional system suggests possible showers)
Wind: 22 km/h
Sailing: Poor; strong waves 2–3 m possible
Tide: Higher tides

20 Nov, Thursday

Temp: 28°C / 18°C
Weather: Cool, mostly cloudy
Wind: 15 km/h
Sailing: Improving, but still moderate waves
Tide: Stable tides

21 Nov, Friday

Temp: 29°C / 19°C
Weather: Cool, partly cloudy
Wind: 17 km/h
Sailing: Moderate; suitable for short trips
Tide: Normal tides

22 Nov, Saturday

Temp: 30°C / 20°C
Weather: Cool, partly sunny
Wind: 17 km/h
Sailing: Fair conditions; waves 1 m
Tide: Normal tides

23 Nov, Sunday

Temp: 31°C / 21°C
Weather: Cool, partly sunny
Wind: 15 km/h
Sailing: Generally good; calmer seas
Tide: Moderate tides

A strengthening northeast monsoon is now affecting the Gulf, bringing more rain, including some areas with heavy to very heavy rainfall along the southern east coast. Sea conditions will be rough, so small boats should stay ashore from 19–23 November 2025.