Since people are asking, here's my list of the events I've compiled that I've found that allow for public nudity. It's a Google Sheet, so I'm trying to update it every now and then.

https://docs.google.com/spreadsheets/d/1QAUgy8z_0ac3V5alfPEs9J2Z9fsvynkgSwFQTBrmscY/edit?usp=drivesdk

Few things:

1) I tried keeping descriptions or allowance of nudity next to their names to try and distinguish which events allow nudity, and which events are just notorious for nudity.

2) Most of these events aren't meant to be sexual (Bay to Breakers, WNBR, etc.). You can show off your body, and enjoy it, without making people feel uncomfortable in doing so. Consent, restraint, and respect; all are important traits to keep if you're trying to attend these events to explore your exhibitionist fetish.

3) I included a tab for Pride events because some of them do allow nudity (Folsom Street Fair is technically a Pride event, but it's supposed to be a sex-positive event). I was hesitant to include these events, however, because I don't condone giving the community a bad name by making an ass out of yourself. If the event allows it, then showing off your body is fine. And if you enjoy it, then that's fine too, as long as you keep yourself under control. But don't perverse what the event stands for.

4) I'm still constantly updating this list. If you have any suggestions, please let me know! Also, I'm from the US, so there's a lot more detail in US events than there are in the rest of the world.