That’s a tough call Brian. Speaker grilles are made of metal or fabric ! The one other type that I can think of is reticulated foam ( think JBL L100). But that disintegrates when exposed to enough UV so I wouldn’t hold out much hope for outdoor use in the Sunshine State. Of course some outdoor speakers that look like escapees from a boombox just have pierced plastic which may do the trick. Incidentally I also have a suspicion that many cone surrounds would fall victim to being fully exposed to your climate.
The word that always used to be used in regard to products to be used at your type of latitude is " tropicalised " - a word I saw a lot here back in the days of Empire ( not that there was much left even then). You could try using it in an email to manufacturers whose products you are interested in. Sonos do say that their Move speaker is weatherproof but what exactly do they mean by that? Can withstand a light shower of rain not exceeding 5 mins in duration?
It all depends too on the standards of sound that you are prepared to accept. Looking around the web there are many speakers that are both Bluetooth and “outdoor” but as most seem to be well under 100 gbp a pop I would not expect too much.