Well, the temp cycle is different than I'm used to; heat peaks here later in the day. It has taken about forever for me to absorb this fact.
I don't remember LA being difficult at night, and we never had a.c. On the other hand, I didn't live in the SF valley, though I was there often enough.
I'd have to look at the valley weather data to look at the patterns. But, LA is a semi arid desert, so point taken.
I also remember Chicago, again with no a.c., with high humidity and temps stayed very hot at night if not at peak, if memory is right. At least discomfort did.