I agree with most of the above comments, I would be cautious of the LA basin and the Marine Layer which is fairly prominent most of the year. I don't think you would suffer too much with density altitude where you are thinking unless your a/c is worn out, underpowered or overloaded as I used to fly in and out of Big Bear in a clapped out 172 full fuel and 3 up in the hottest weather and still attain 300 ft/min
If you wanted virtually guaranteed flying every day the Vegas/Nevada area is generally superb and there are some good rental places at North Las Vegas airport that can offer you the latest as well as the cheaper single pistons to rent at reasonable prices