The Short Answer
Spanish mackerel are one of Thailand's most reliably available pelagic species — present somewhere in Thai waters in fishable numbers during every month of the year. The Andaman coast peaks from December through March, when northeast winds bring calm seas and productive current lines. The Gulf of Thailand delivers its best fishing from September through December, as northeast winds push bait along the gulf's western shore. If you're flexible on destination, you can effectively chase peak-season mackerel year-round by moving between coasts.
Andaman Coast: December to March
The Andaman fishing season opens properly in November and runs through to April, but the three months from December to February are when Spanish mackerel fishing is most consistent. Calm seas allow access to offshore current lines and the reef edges where mackerel ambush bait. Visibility is high, trolling spreads can be worked at speed, and the fish tend to be in good condition — solid, well-fed, and fast.
Prime Andaman locations include the reefs and offshore banks around Phuket, the waters southwest toward Racha Yai and Racha Noi, and the offshore structures accessible from Khao Lak. Day charters from Phuket reach productive mackerel water within an hour in most cases, which makes this one of the more accessible pelagic targets on the coast.
The Andaman season coincides with Thailand's high tourist season, so charter availability can tighten in January and February. Book vessels at least a few weeks ahead if you're visiting during the peak window.
March remains excellent. April sees conditions beginning to soften as the southwest monsoon approaches, and by May the Andaman is largely closed to offshore fishing. The monsoon period — May through October — is not a realistic Andaman mackerel window for most anglers, though some calmer inshore areas remain fishable.
Gulf of Thailand: September to December
The Gulf operates on a different seasonal rhythm to the Andaman. The southwest monsoon, which closes the Andaman, actually delivers some of the gulf's best fishing — particularly on the western Gulf coast around Chumphon, Koh Samui, and Koh Tao. September through November sees the northeast monsoon beginning to establish, and with it comes the bait movements that Spanish mackerel follow.
October and November are widely considered the prime Gulf months for pelagic species in general. Spanish mackerel are active along current breaks, around reef structure, and near the bait aggregations that accumulate off headlands and island groups. December is a solid month as well before the northeast monsoon starts to push seas up on the gulf's eastern flank.
From Pattaya and the eastern Gulf, October through December is a productive window. Waters off Rayong and east toward the Cambodian border also produce Spanish mackerel during this period, with the fish following bait pushed down the coast by the northeast wind.
Spanish mackerel don't wait for perfect conditions — they follow the bait. Learn to read current lines and bird activity, and the fish will tell you where to be.
Year-Round Availability: What It Means in Practice
The two-coast seasonal pattern means that for most of the calendar year, there is productive Spanish mackerel fishing somewhere in Thailand. Roughly speaking:
- November–April: Andaman coast is the primary focus
- May–August: Reduced options on both coasts; inner Gulf remains partially fishable
- September–December: Gulf of Thailand comes into its prime
This overlap is particularly useful for anglers based in Bangkok or the central Gulf region, who may not want to travel to the Andaman coast. The Gulf season delivers comparable fish sizes and can produce exceptional days when conditions align.
Methods and Tackle
Trolling is the most widely used method. Diving hard-body lures in the 10–15 cm range, chrome spoons, and rigged baitfish are all effective when worked at 6–8 knots across productive ground. Wire or heavy fluorocarbon traces are standard — mackerel have sharp teeth and will cut through light monofilament.
Casting to surface-feeding fish is highly productive when schools are located. Metal jigs, chrome slices, and soft plastics cast into feeding activity will draw aggressive strikes. This is excellent sport on light spinning gear in the 15–20 lb class.
Trolling for mackerel as a secondary species while targeting sailfish or wahoo is common on Andaman liveaboard and day-charter trips. See our guide to light tackle charters in Thailand for operators who run dedicated mackerel and mixed-species light-tackle trips.
Reading Conditions
Beyond the seasonal calendar, the most reliable daily indicator for Spanish mackerel is surface activity. Feeding mackerel push bait to the surface, attracting terns and other seabirds. A cloud of birds working a patch of water is one of the most dependable signs in tropical pelagic fishing, and mackerel are often the species responsible.
Current lines — the visible boundaries where water masses of different temperatures or colours meet — concentrate bait and, accordingly, mackerel. Experienced charter skippers spend as much time reading the water surface as they do watching the sonar.
Plan Your Trip
For full species detail including identification, size records, and tackle recommendations, visit the Spanish mackerel species page. For a broader view of seasonal patterns across Thailand, our guide to the best time to fish in Thailand covers all major species and both coasts in one place.
