make RenderSettings Fog stay on

I press play to test my scene and then go to renderSettings to turn on and customize fog. Great! - That is until I stop the scene from playing, the fog goes away and my values are gone too…Is there a way to make the fog values stay permanent so i don’t have to keep setting it up every time I press play button? Please advise.

Changes made in Play mode aren’t saved. Change them in edit mode, then hit Play.