Rain is really much better...wish I have rain here on my side.
I am inclined to just leave it like that, just because Fall is coming and very soon it will be much cooler on your side already, and the plant will go to dormancy. It is different if it is still late Spring, there would be still 3 to 4 months of sun and heat which the awakened Plumeria will enjoy a lot with stepped up watering.
Watch your outdoor temps, when my Plumeria was younger, once it starts hitting 50F and below overnight, I pull it back indoors, positioned by our south side window and watering is scaled back.
