If they will be in there all the time, it will be too hot in summer. It may even be too hot at night because of the high humidity. Wind that would help cool it dies out in the evening in the summer here, so if you have the same type of summer, you would still need a fan.
Even though my coop was in the shade, (I am FL) I ended up putting those ice packs on the roof at their bedtime to help chill the upper area. I would wave them around inside to cool that air rapidly!
I added way more open area with windows and enlarging vent holes.
Now my newer coop is all wire except the top and one wall. I also will be adding insulation to the roof. (Ever sit on a patio that has no insulation between you and the roof? Like an OVEN) I hang plastic and towels for bad weather, cold. My youngsters did fine with a few 30 degree nights like that. I don't secure the plastic, so they still get air exchange.
The best thing I did was getting a silver tarp for over their area. I got the heavy duty one, with brown on the other side. It makes such deep shade it is the coolest spot besides the air conditioned house. It also gives them a dry place in the rain.