Seasonal· Koh Lanta Yai· Thailand
Southwest Monsoon: No West-Coast Anchorages (Lanta)
7° 36.9′ N · 99° 0.9′ E · approximate
From about May to October the southwest monsoon sends swell and wind straight onto Lanta's west coast, and every beach anchorage from Khlong Dao to Khlong Chak becomes untenable. The east coast and the inner islands stay usable year-round.
Practical
Southeast Asia Pilot: the west coast offers many anchorages in the NE monsoon but none in the SW monsoon. Shelter moves to the east side: Koh Po and Talat Lanta (moderate protection), Koh Kam Yai (excellent in both seasons) and Koh Talabeng (perfectly protected). In the Trang islands, Koh Ngai East is the SW-season choice, while Koh Muk West, Koh Muk South and Koh Kradan West are NE-monsoon stops. Most park islands also close in this season: Mu Ko Lanta's smaller islands from 16 May to 14 October and Koh Rok from 1 June to 30 September (thainationalparks.com, 2026). Most Lanta dive shops close from about the end of April to late October (Wikivoyage). Transitions between monsoons bring variable winds, so plan an alternative anchorage. Position approximate: a point off Lanta's northwest coast, used only to place this note on the map.
Best for
Planning which side of Lanta to use
Season
SW monsoon roughly May-Oct