“…it seems to me that rain is a mirror of one of our key emotional states: not a negative one at all, but deeply necessary – just as necessary as joy. Water, after all, both reflects us, and brings life; it was also, for Jung, an archetype of the unconscious, and of change. ‘Into each life some rain must fall,’ wrote Henry Wadsworth Longfellow (or was it Dennis Potter?) – and it’s quite true: after all, nothing new can grow without it.”
Rain: Four Walks in English Weather, Melissa Harrison.