Here is a spreadsheet showing the weather from day-to-day in Krabi, Thailand during part of the year.
Everyday I wake up and look out the window and put a note down about the weather in Krabi. You can use this to help plan your vacation, by seeing the times of the year when it rains. There are small cycles the weather gets into, which continue for a couple of days.
You can guess what your weather will be like when you visit Koh Phi Phi, Ao Nang, Krabi Town, or other areas in the province.