Andaman Sea ferry weather
Check waves, wind and monsoon conditions across the Andaman Sea today and tomorrow, with guidance for ferries and speedboats between Phuket, Krabi, Phi Phi and Koh Lanta.
Fast craft can feel very different from larger ferries in the same sea. Check the live outlook, the vessel type and the operator before departure.
Andaman Sea outlook
Waves to 0.4 m · 7 kt winds · gusts 12 kt
Calm outlook for most ferry passengers.Waves to 0.4 m · 8 kt winds · gusts 13 kt
Calm outlook for most ferry passengers.Currently looking broadly similar to today and tomorrow.
5-day trend · Lower confidenceGenerally comfortable conditions on a conventional ferry.
The Andaman Sea is a ferry network, not one single crossing
The Thailand side of the Andaman Sea contains one of Asia’s busiest island-ferry networks. Phuket, Krabi, Ao Nang, Phi Phi and Koh Lanta are linked by a mix of conventional ferries and fast speedboats, often with several departure options on the same corridor.
That mix matters for weather. A sea state that feels manageable on a larger conventional ferry can feel much sharper on a small fast craft. For passenger comfort, check both the forecast and the type of vessel you are booking.
Andaman Sea wave forecast
Use the map for the water between the islands, not just the weather icon at Phuket or Krabi. Conditions can be noticeably rougher once a speedboat leaves the lee of the coast or an island.
Southwest monsoon weather matters most for Andaman ferry comfort
Thailand’s rainy season normally begins around mid-May as the southwest monsoon becomes established. On the Andaman side, stronger monsoon periods can build rougher seas, while thunderstorms can produce locally higher waves than the wider background forecast.
This does not mean every wet-season ferry is rough or cancelled. It means conditions deserve a closer check, particularly when travelling on a speedboat or when the marine forecast highlights the upper Andaman Sea.
Southwest monsoon
Wind, rain and rougher periods become more frequent. Stronger monsoon episodes can affect exposed ferry and speedboat routes.
Often more settled
Longer calmer windows are common on Thailand’s west coast, although thunderstorms and isolated rough periods remain possible.
Hot transition period
Heat and developing thunderstorms can matter even before the full southwest monsoon pattern is established.
Check the actual sailing
Short-lived squalls can change conditions quickly, so use the live forecast and operator information close to departure.
Where Andaman Sea ferry weather matters most
These corridors carry a mix of ferries and speedboats. Crossing time can vary substantially depending on the vessel and whether the service runs direct or via another island.
The same 1-metre sea can feel very different
Andaman routes are unusual compared with many European ferry corridors because passengers can often choose between a larger ferry and a much smaller fast boat. The smaller craft accelerates and reacts more quickly to short waves, so passenger movement can feel sharper even when the headline wave height looks modest.
If you are prone to motion sickness, a slower conventional ferry may be the more comfortable choice when the forecast is active. Read the fast ferry versus large ferry guide and the seasickness guide before choosing a departure.
Thunderstorms can create locally rougher water
Thailand’s marine forecasts regularly distinguish between the background sea state and higher waves in thundershowers. That is useful for ferry passengers: a regional map can show manageable conditions while a passing squall temporarily produces stronger gusts and steeper waves along one part of the route.
For that reason, do not judge an Andaman crossing from a single wave-height number. Combine the live sea forecast with thunderstorm warnings and the operator’s latest departure information.
Complete the Andaman Sea weather check
Use FerryWeather for the passenger-focused sea picture, then confirm local marine warnings and your specific departure.