Rainy Season SEA

Hi I am planning on going to south east Asia as soon as possible for 1-3 Months. I’ve never travelled to Asia so I was not aware of the rainy season but my original plan was to leave for the trip at around mid June but of course knowing about the rain I’ve backtracked. My plan is to go to Thailand, Vietnam, Laos, Cambodia, Philippines and a couple of days in Singapore. Is there a route I can take to avoid the rain as much as possible or is it worth waiting. If I wait what would be the best month to start, google says November but you can’t always trust google 😅