It will never be cooler than ambient temp, of the intake, and will be several degrees warmer. How hot will depend on your lighting, and ventilation. Many growers, at least here in the south, quit growing, in the summer, for just this reason. I have heard, but don't know for sure, that at anything over 80 degrees F, that plant growth stalls out.
If you are planning on another grow, over the summer, I would find some way to air condition, your intake air. There is a thread, here that shows how to make a do it yourself AC. You may be able to use that.
Best of luck bro.
Green Mojo sent.
HomieHogleg