How can you use rain as a metaphor?

Rain being used in a metaphor is common and an easy metaphor. Here is one of the more popular or common metaphors used relating to 'rain'. If you were describing a sad person you could take the sentence, "She cried," and switch it around. You first should start small with a simile; "When she cried it was like rain." Then make it a metaphor and as you know a metaphor does not use 'like' or 'as'. "Her crying was rain," or something similar pertaining to rain or perhaps other weather conditions. Using 'rain' as a metaphor is quite easy plus you can explore the other weather metaphors!