Absolutely that is not weird. Some people enjoy being naked and outdoors. The freezing rain part might not be everybody's cup of tea.
I had a boyfriend that we used to go camping in the Canadian wilderness. We loved being outside in the wilderness. Even in the rain. It wasn't 100% of the time, but there is something so freeing about it.
As for getting off outside. That's not strange. You are so thrilled by the experience, you get the urge. That might wear off as you go outside naked more and more.
You might want to look into nudist colonies. Though, you might have to get the erections under control. I could never do a nudist colony. But when in France 2 summers ago, I did go topless on the beach. It was exciting doing it. But again, the more one does it, the less the thrill I would assume. jmo