Hi!
Although HH is not our home resort, we've been the past two years at spring break. The weather has been great for us. Both of our breaks have fallen at the end of March (one with Easter holiday, one without). I remember needing a lightweight jacket a few times the first year--but we did swim. And this past year we swam a bunch!
It's a great time to be there. Lots of fun resort activities.
You'll love it!
~Laura