To clarify, if you go to your preferences, you'll see an item under "Content options" saying "Disable holiday styling". Clicking this is what will turn off the snow effects. Changing your skin is entirely separate from this.
For now, given all the feedback I've seen on this snowflake effect, I'm manually disabling that globally. You should still have all the other static snow effects showing if you have holiday styling enabled.
Yeah, to add onto this better late than never: I disliked the falling snow so much that I spent half an hour adding it to my adblock filters. While you may be able to disable it through your settings, if you're private browsing on mobile or whatever otherwise not logged in, you can't do that. It was way, way worse on mobile with the flakes having the same size. They even appeared to occasionally block taps.