It would have to be a lot more than that. As a rule, rain is produced by large lakes and seas, and some evaporation from tree cover. At a guess, I suppose Iran would get precipitation from the Gulf and Caspian, maybe the Mediterranean to a lesser extent, and some of their water renewal must be off snow melt.

I flew over Iran many years ago. Much of it reminded me of central Australia. Very arid and desolate, but beautiful from thousands of feet up.