As for a literal interpretation, I think only Randy can answer that. But as a personal meaning this song describes very well the feeling of being alienated, or more profoundly that the world isn't what you thought it was. If you ever saw the movie "Bruce Almighty", he says "let it rain", and the next scene he's in his living room feeling awful about the circumstances he's in. I think Randy was saying the same thing, "Screw it all! Just let it rain so everybody can be as miserable as me."
As for a literal interpretation, I think only Randy can answer that. But as a personal meaning this song describes very well the feeling of being alienated, or more profoundly that the world isn't what you thought it was. If you ever saw the movie "Bruce Almighty", he says "let it rain", and the next scene he's in his living room feeling awful about the circumstances he's in. I think Randy was saying the same thing, "Screw it all! Just let it rain so everybody can be as miserable as me."