Rain in a dream can represent more than one thing depending on the context.
When it’s a nice and sunny day, and rain drops appear, it’s a foreshadowing of unfortunate circumstances that is to come. It represents a problem that you’re going to face within the near future, or a problem that you’re currently facing. Conquer your problems and your dreams will clear up.
When you’re in the rain, in a sense where no one is around, represents loneliness within your life. It represents how there is no one around you, and that you have no one to be with. You’re standing all alone in the rain, and no one is there.
When there’s rain and you’re looking upon it from a perspective, it means peace and subtlety within your life. There is a calm period and a time for relaxation. There is currently no problems you’re facing and you need to enjoy this time.