The two seasons in Langkawi are the "Wet" South West Monsoon from June to October when prevailing winds of 10 - 25 knots are from the south west. The "Dry" North East Monsoon is from December to April,
with mainly 5 - 20 knot north east winds. May and November are the
'in-between-seasons' transitional months with variable winds.

A brief summary of the main weather features for each month:

December, January, February: Mostly fine & sunny. Great sailing with NE winds.
March, April:  Some showers & late thunderstorms. More humid. Light NE winds.
May:  T'storms & humidity increase as rainy season approaches. Winds variable.
June, July:  Rain most days. Strong SW winds and possibly 30-50 knot Sumatras.
August:  Less rain but strong SW winds. Some sunny days with occasional showers.
September, October:  Back to rain, strong SW winds & some 30-50 knot Sumatras.
November:  Less rain, more sunshine and variable winds, slowly going back to NE.