Central midwest here - just went out on my lunch break, it's about 38F with ample sun. Felt great by the end of my 30 min session, decent sweat going and popping some solid ollies.
Yesterday was actually colder despite it being warmer out, about 44F. I even saw another skater in my apartment complex when I went for a walk after work so I felt some solidarity haha. As others have said, the breeze/wind will absolutely ruin the fun! It sucks tearing up while trying to skate, or sniffling like crazy.
My limit is about 35F depending on the sun and wind. I don't usually go to parks in the winter unless it's 45F or warmer. Not visiting the indoor park lately bc of COVID raging. My limit is pretty low bc I'm a lazy 28 year old, but I do get cooped up and want to skate as much as possible. Grateful for the past two days being warm enough.