Is this something people would say, or is it too redundant? The translation was standard.
You must say it. "yağmak" doesn't just mean rain falling, it can be other forms of precipitation. E.g. kar yağıyor it's snowing, dolu yağıyor it's hailing
-mUr is not a productive modern suffix. Just a super old one to make nouns out of verbs.
There are very, very few clear examples of it in modern Turkish, and even those are often speculative. Apparently other than yağmur there's only "kömür" coal (from an extinct verb "köymek" to burn), and damar vein (coming from extinct tamur, coming from extinct verb tammak to drip, existing today as damlamak).
I know damar! My grandma uses it all the time. That's a very interesting lesson, thanks.
Can't i say "rain is falling" as a translation as well? It sounds more literal