Andaman Sea — May 2026 Report
Every May, the Andaman Sea delivers a version of the same message: the season is not over, but the clock is running. The southwest monsoon builds from the south and west across the Bay of Bengal, and by the time it reaches the Andaman coast of Thailand it reshapes everything — sea state, sky, and the operational calculus of every charter captain running out of Khao Lak and Phuket. May 2026 followed this pattern with reasonable fidelity. The first two weeks offered fishable windows that produced some of the season's final memorable encounters. The third week turned marginal. By month's end, the offshore charter season was effectively closed.
Weather and Sea State
The transition this year was gradual rather than abrupt. A persistent ridge of high pressure held conditions relatively stable through the first ten days of May, allowing experienced captains to make the run to offshore structure and the northern pinnacles on days when the swell remained manageable. Afternoon cells built quickly and unpredictably, which compressed usable fishing time into morning-only windows on many days, but the fish cooperated.
By the third week, groundswell from the southwest increased markedly, and conditions at the outer reefs and offshore grounds became difficult for all but the largest vessels. The final liveaboard departures from Tap Lamu port wrapped up during this period, completing seasonal routes that had been running since November. Captains noted the transition as roughly on schedule — perhaps slightly earlier than some recent seasons in terms of the sea state deteriorating, but within the expected range.
Sailfish — Season's Closing Chapter
Sailfish had been the signature species of the 2025–2026 Andaman season, and May provided a fitting close. Captains running trolling and live-bait presentations in the first two weeks reported encounters on most fishable days, with fish congregating around temperature breaks and baitfish concentrations along the hundred-meter contour north of Phuket. The action wasn't the frenzied multi-release days of peak February and March, but it was genuine — a single boat on a good early-May morning might raise four or five fish and convert two or three.
Captains running out of Tap Lamu noted unusually strong wahoo activity around Koh Bon during early May — a welcome bonus as the sailfish season wound toward its close.
The wahoo bonus was a recurring mention in reports from the northern grounds this month. Faster trolling presentations targeting wahoo around offshore structure produced fish that surprised anglers who'd come expecting to chase sails. High-speed skirts and large metal lures worked the edges of reef structure produced wahoo that were notably good-sized.
Giant Trevally — Final Popping Days
GT popping on the Andaman's offshore islands and pinnacles enjoyed a brief but productive final window in early May. Conditions at the better-known popping grounds were fishable during the calm mornings of the first week, and small groups of dedicated popping anglers made the most of it. Surface strikes on large poppers over shallow reef structure remained aggressive, and fish were well-conditioned after the long season on abundant baitfish.
The window for popping closed faster than trolling this year. Once the southwesterly swell established itself, working close to reef edges and managing boat position in any kind of sea became genuinely hazardous, and experienced guides sensibly called the season. For GT chasers who came close to booking but didn't commit, October on the Andaman will reset the clock.
Inshore and Estuary Fishing Continues
While offshore operations wound down, the inshore picture remained viable and will continue to be so through the monsoon. Mangrove jack along the creek mouths and mangrove channels around Krabi, Phang Nga, and Ranong responded well to lure presentations throughout May. Queenfish showed at tidal river mouths around the new and full moon tides. Estuary barramundi, though not the headline attraction this region is known for, provided solid sport for anglers willing to work smaller waterways close to shore.
For those staying in the Khao Lak or Phuket areas through June, guided inshore and estuary fishing offers a genuine alternative to the now-closed offshore season. Cheow Lan reservoir, a few hours east of Khao Lak, is a serious freshwater option — its peacock bass and giant snakehead populations make for compelling fishing regardless of what the Andaman is doing.
Liveaboard Season Closes
The final liveaboard departures from Tap Lamu completed in mid-May, ending a seasonal run that had logged impressive accumulated catches. Operators reported a strong 2025–2026 season overall, with conditions during the November–March peak delivering consistent sailfish action and several notable GT and wahoo days. The northern route through the Similan chain and beyond produced reliably through April, with the May departure schedule compressed as conditions became less predictable.
The Similan Islands National Park closes to all visitors in mid-May and typically reopens in late October. Any charter or liveaboard itinerary including the Similans must depart before the park closure date — confirm departure windows directly with your chosen operator.
Looking Ahead
June through September is effectively the Andaman's off-season for offshore fishing. Inshore and freshwater alternatives are the play for anglers who find themselves on the Andaman coast during these months. The season proper reopens in October, and November brings the first serious sailfish action of the 2026–2027 cycle. For anglers planning ahead, November and December bookings on the better-known charter vessels fill quickly — contact operators well in advance.
Recommendations for Visiting Anglers
If you're reading this in early May with a potential Andaman trip in mind, move quickly. Fishable days are still possible in the first two weeks, but conditions can shift overnight and reputable operators will call trips rather than run in unsafe seas. Flexible cancellation terms are essential on any May Andaman booking. For anglers planning a dedicated trip, waiting for October and targeting the full offshore season is the more reliable approach.
