The roof has 12" of overhang and the vent is only 4" tall. It would have raining sideways to get in. which does happen here, but not often.
The big white coop 8x24 in background of some pics does get rain in it. It has a 12" of overhang and 2 foot opening all the way around. I didn't build it that way, but i'm going to fix it.