In the tropics, the temperatures are sustained, does not go down below 70F, so even if Adeniums gets rained on, as long as drainage is very good, it can sustain the wet conditions. Unlike here in the US, our temps fluctuate so Adeniums still has to be protected when prolonged downpour is in forecast.
I remember looking at several Adeniums in nurseries in Manila and also at my mom-in-law's place. They are growing in such abandon, very fat caudex and blooming happily. Trying to think what is different, they have that high humidity and warm to hot temps day after day.
