Gulf of Thailand weather forecast: what the week of 17–23 February 2025 means for your crossing
This Gulf of Thailand weather and tide forecast covers Koh Samui, Koh Pha Ngan, Koh Tao and the mainland port area of Surat Thani for the week of 17 to 23 February 2025. Sea conditions on these routes are generally settled: waves stay around 1 metre all week, and tides are reported as normal every day.
Daily forecast, 17–23 February 2025
- Monday, February 17: Temperature: 27°C - 32°C. Weather: Partly sunny. Sailing Conditions: Waves ~1m, calm seas. Tide: Normal
- Tuesday, February 18: Temperature: 27°C - 30°C. Weather: Mostly cloudy, light rain. Sailing Conditions: Waves ~1m, slightly choppy in rain. Tide: Normal
- Wednesday, February 19: Temperature: 27°C - 30°C. Weather: Morning thunderstorms, light rain. Sailing Conditions: Waves ~1m, occasional higher swells during storms. Tide: Normal
- Thursday, February 20: Temperature: 27°C - 30°C. Weather: Cloudy morning, sunny afternoon. Sailing Conditions: Waves ~1m, stable conditions. Tide: Normal
- Friday, February 21: Temperature: 27°C - 30°C. Weather: Mainly cloudy, light rain. Sailing Conditions: Waves ~1m, slightly rougher in rain. Tide: Normal
- Saturday, February 22: Temperature: 26°C - 30°C. Weather: Morning showers, cloudy afternoon. Sailing Conditions: Waves ~1m, occasional slight increases. Tide: Normal
- Sunday, February 23: Temperature: 26°C - 28°C. Weather: Periods of rain. Sailing Conditions: Waves ~1m, choppy in rain. Tide: Normal
How the week develops
Monday is the warmest and calmest day, with partly sunny skies, a high of 32°C and calm seas. From Tuesday onward cloud and light rain take over, and Wednesday brings morning thunderstorms with occasional higher swells during storms. Thursday clears in the afternoon and is the most stable day of the week. The weekend turns wetter and slightly cooler, ending with periods of rain and choppier water on Sunday.
Who this affects
These conditions matter most to travellers crossing between the mainland and the islands, and to anyone island-hopping between Samui, Pha Ngan and Tao. Around 1-metre waves are within normal operating conditions, so significant disruption is not expected — but morning thunderstorms and rain squalls can make individual departures feel rougher, and open-deck or smaller vessels feel motion more than larger ones.
Practical tips for travelling this week
- Book morning departures where possible on stable days, and allow buffer time before onward flights or connections.
- Pack a light rain layer and keep bags and electronics in a dry bag or sealed pouch.
- If you are prone to seasickness, take medication before boarding on the rainier days and sit low and central on the vessel.
- Check your operator's updates on the day of travel — departures can be adjusted at short notice.
Plan your route
Compare timings and availability for Surat Thani to Koh Samui, Koh Samui to Koh Pha Ngan and Koh Pha Ngan to Koh Tao, or browse everything serving Koh Tao to build your island-hopping plan.
Disclaimer: Weather, sea conditions, and tide information are subject to change. Always check local updates and forecasts before planning activities.
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