I would not say 30 degrees is cool but I get what you mean. My apartment room is facing west and the temperature was around up to 30 degrees in the late afternoon. It was bearable without using air conditioning. This was the upstairs room which is close to the roof. The downstairs was much cooler. Probably around 24-25 degrees at most. I do not know my apartment is well built like yours, but thankful that it does not get too hot.