I was able to kite 4 days out of 4 in Thailand in August at a spot called Laem Son in Rayong province.
Its a quiet part of Thailand and not many westerners travel here.
Which kind of makes it special... you could say this is the real Thailand.. not like Phuket and Koh Samui
And this place seems to get alot of wind May to October from what ive heard.
Mostly 13-18 knots but good enough to have fun.
I filmed a short movie of it if you want to see what its like.
http://www.youtube.com/watch?v=WPrpuHWmUqk
and yes im surprised as anyone who has been to Thailand around this time and hoped (not expected) for wind... it really does blow