is it reasonable to go to volcano bay at the end of march? what are the water temps at this time? are the pools heated?

I just took my family in the beginning of March and although we had fun, we were absolutely cold. It was maybe 83°F, but windy. While the pools seemed to be a bit warmer, the slides and kids Runamukka Reef were freezing. I guess "heated" is relative. Standing in lines while wet and cold, even with the Tapu Tapu pass, was not fun.

I work with Universal and it's definitely warm enough and the water is heated. The only things to keep in mind would be that thunderstorm season is slowly creeping upon us and spring break lasts basically for a month. It could be at capacity by 11 or 12pm

Not sure about Volcano Bay

Absolutely! It was 90 degrees i2n Feb!

It's definitely warm enough for it But i would watch out for the spring break people, it will get busy