Weather was hit and miss. New orleans I wore clothes I was wearing in Canada because I was freezing - so I'd pack layers, especially as for Mardi Gras you are sitting outside for hours.
It was pretty windy most of the cruise so the ship was swaying quite a bit, even house keeping I was talking to had said the cruise before it hadn't been that warm.
Honduras, was hot and humid - I think it was in the 90s
Belize was damp, we arrived just after a storm so you could feel it in the air the coolness. I wore long pants (these, they are pretty light but I wouldn't have done shorts). I also had like a tank top and a rash guard long sleeve top on. Others had made comments that I was smart because they were cold - I also had read the excursion details were it said wear long pants because of the boat ride I guess - maybe also bugs a bunch of people got mosquito bites,
Mexico was warmer but I don't know if it was warm enough for the beach. I remember some excursions being cancelled but can't remember if it was just Belize or Belize and Mexico.
So I purchased when OBC was included so being solo it racked up quite a bit. All of my excursions were through the ship, some countries I'm ok being solo but not these I rather stay with the ship.
Honduras - Experience Roatan's Fauna
Belize - Lamanai Mayan Ruins and Riverboat Safari (this one is a LONG day, first you had to take a tender to shore, then a hour or more bus ride, then a river boat to the ruins. So same coming back, but when coming back a second storm was rolling in so the tender ride was bumpy and difficult for some people to get off - mainly those with mobility issues)
Mexico - I didn't do one as mine was cancelled night before so didn't have time to plan something else.