Weather decision Hoi An/Da Nang & Con Dao

Hi all, I’ll be in Vietnam from 22nd of April till 12th of May. I would like to visit Con Dao & also Hoi An & Da Nang for a longer time during my trip. Normally I wanted to go to Con Dao at the end of my vacation so 5th till 10th may ish. Now I’m not sure, if it’s a good season for the island cause they say that it’s raining a lot in May. Any experiences here? If it’s too risky then I would start with Con Dao and do Hoi An/Da Nang at the end.

Thanks!