August can be a very wet month on the Andaman Sea side of Thailand and the sea can be very rough, but prices are low so if the budget is tight and you dont mind some rain it can still be pleasant.

I would much rather the Gulf Islands at this time of year...Samui/Phangan/Tao. It is much busier and you will pay higher rates but the weather is reliable, seas are flat and everything is open and operating.

__________________
I love Thailand this much