Originally Posted by a45wg
Based soley on my expierience from last year in July/Aug - this time of year is not good for sailing around Langkawi.
The best places to cruise are the Island on Langkawi itself, or clear out and head up towards Thailand. The only problem with this is the North East Monsoon, can be straight in your face (even though Phuket is NNW).
Hope this helps
I understand topic's question to mean " sailing around Langkawi in/from September 2008"
Essentially there is no difference in the tropical waters of South East Asia during the South West Monsoon - which is the rainy season north of the Equator. The best weather in terms of less rain and cooler conditions starts in October when the monsoon begins its transition to the North East.
This monsoon usually becomes entrenched by the beginning of December (but cooler winds come in by mid November)
To illustrate the South West Monsoon and cloud conditions here are today's WX. jpg and gif:-