Should I wear ?

Hawaiian Shirt on August 2 For the weird Al concert?

strange question, but you can wear whatever the hell you want that is comfortable and does not break decency laws where you live. I laugh in the face of faux pas.

Mama ain't around, do your thing.

The man literally has a song about poor clothing choices, I think you're good wearing whatever :P

And every other day.

I went to his portland show and there were lots of Hawaiian shirts there, so I think it’s fine. It’s not quite the same as the old “wearing the t-shirt of the band you are going to see” faux pas, which is never really understood anyway. Wear what you like.

I wore a hamtaro sweater out a few nights ago and I've never gotten more compliments in my life. Do what makes you happy and it'll probably make others happy

Wear whatever you feel like it, if its appropriate to the weather.

Also, a Hawaiian shirt in a Weird Al concert seems very appropriate...

Weird Al remains one of the least pretentious, longest-term successful musical acts out there.

Frankly: I think you won't stand out at all.