it's not.
It's competely open and depending on how the wind blows determines the sound. and if it's low tide you get the most god awful stench from Zaks bay.
Lucky for me I have never had "weather" issues at any of the shows I've seen there but outside of intense lightening the show goes on....so if it's just raining...you sit in the rain...
The
only positive thing about JB is I live so close to it.