As far as we can tell, yes. Surfaces are generated by the same seed and algorithms that generate the planets themselves. So they will always look identical (once the day/night ciycle is taken into account), no matter who visits them or when.
Example: Earth. The coastlines are always the same (obviously), but the cloud pattern is identical each time you visit it as well. There's always a hurricane over Greece and Italy, rain clouds over central Australia and the British Isles are permanently fine and sunny. The same holds true for all other Earth-likes in game, both inhabited and non-inhabited.
Example: Glowing Green Giants. The ls and streaks of bright green are always identical in pattern and position relative to each other. Storms don't spin and rotate, stripes don't change colour or move about.
If you're considering some kind of "surface mapping project" for Earth-likes, for example, I personally wouldn't recommend investing too much time or effort; while such worlds are constant for now, they will likely change radically once they are made landable. Consider how much the geography of airless landables changed once Horizons launched and we could land on them; they look completely different now compared to then (this is something you can check for yourself, just by flying up close to a landable planet, taking a screenshot, then quitting and firing up the base game and taking another screenshot. I suspect Earth-likes, Gas giants etc will all suffer the same transmogrification if/when they in turn become landable.
