There are not different rains there is only the one rain falling from the single cloud. The Buddha in his skillful wisdom knew what each of his disciples was capable of understanding. He taught according to that capacity with the objective of eventually leading them deeper so they could partake of the complete Dharma. This is one reason why we say that previous to the Lotus Sutra the Buddha taught according to the minds of those he was teaching, and in the Lotus Sutra the Buddha teaches according to his own mind.