I used to live in Poway and the heat can be unbearable. Having to run the AC just so you can get to sleep at night is common during the summer. I moved to pacific beach 25 years ago and never looked back. Over 20 years ago, we turned off the gas to our heater and haven’t turned it back on. We don’t have AC and there are only about ten days a year that it gets somewhat uncomfortable. Nothing you can’t live with. Poway is not as bad as Palm Springs but it’s close.