"It isn't raining any more" is the right way to say this, because it means "it is no longer raining," implying that the rain stopped *for now.* If you say "it doesn't rain any more," you are implying that it will never again rain where you are. In English, the simple present tense often refers to a "general truth" or "a habitual occurrence." So saying "I go to Church on Sundays" means "I go to Church every Sunday, now and in the future." Likewise, saying "it doesn't rain any more" sounds like you're saying "it is not raining now, and it won't rain again in the future."

doesn't = Present Indefinite = single or regular action isn't = Present Continuous = action in the process in this situation it was important to see rain as the action in the process which stopped