Seasonal Coastal Conditions in Thailand

Coastal conditions vary in somewhat of a predictable pattern. This information may be especially useful for persons taking surface craft to island destinations. Scuba divers will also be interested.

During months when large waves are predicted, you may be more comfortable flying.

Andaman Sea - Expected Weather Conditions
MonthsUnderwaterSurface
Jan-MarExcellentCalm
AprGood/ExcellentCalm/choppy
May-OctPoor/GoodChoppy/rough
Nov-DecGoodChoppy
Comment: recent years have seen east winds strengthen and may prevent smaller boats from reaching distant sites
Koh Phi Phi - Expected Weather Conditions
MonthsUnderwaterSurface
Jan-AprExcellentCalm
May-JulGoodChoppy
AugFairChoppy
SepFairChoppy
OctFairChoppy
Nov-DecExcellentCalm
Comment: Protected because of location
Koh Lanta Area - Expected Weather Conditions
MonthsUnderwaterSurface
Jan-AprExcellentCalm
May-JunFairChoppy
Jul-AugFair/PoorChoppy/Large waves
Sep-OctPoorLarge Waves
NovGoodChoppy
DecExcellentCalm
Butang Group/Koh Tarutao - Expected Weather Conditions
MonthsUnderwaterSurface
Jan-FebGoodChoppy
MarFairChoppy
AprFairCalm
MayGoodCalm
Jun-AugExcellentChoppy
Sep-OctExcellentLarge waves
Nov-DecExcellentChoppy
Comment: winds from the west - clean clear water from the Indian Ocean depths
West Gulf of Thailand - Expected Weather Conditions
MonthsUnderwaterSurface
Jan-FebFair/GoodChoppy
MarExcellentCalm
Apr-JunFair/GoodChoppy
Jul-AugExcellentChoppy
SepExcellentChoppy
OctExcellentCalm
Nov-DecPoorLarge Waves
Pattaya - Expected Weather Conditions
MonthsUnderwaterSurface
Jan-MarExcellentCalm
AprilFairLarge Waves
MayFairRain, large waves
June-AugGoodChoppy, SW
SepExcellentSome rain, flat seas
OctPoorRain, storms
Nov-DecGoodChoppy, NE
Note: SW=Southwest Monsoon   NE=Northeast Monsoon
Koh Chang - Expected Weather Conditions
MonthsUnderwaterSurface
Jan-MarExcellentCalm
AprilFairLarge Waves
May-OctPoorRain, large waves, SW
Nov-DecGoodChoppy, NE
Note: SW=Southwest Monsoon   NE=Northeast Monsoon