Just a couple of things to add...
Indeed, SW monsoon is still in full swing out west in Thailand. It usually clears up around late October. It's particularly heavy this year and is affecting the east coast considerably also, which is unusual. NE monsoon was light this year (Nov-Feb), and when this happens it's not unusual for the opposing monsoon (SW) to be more brutal.
WX at Krabi was considerably better, although raining. I assume this was the alternative...?