I frequently visit my oldest sis and bro-in-law in NorCal (San Jose to be exact) and to me it's beyond too cold there. True, I consider anything below 75-degrees to be cold and practically shiver when the temps are down in the 50s here, so I know I'm the extreme case.
Back in MI I kept my apartment temp around 90 degrees (even in the summer), so that prepared me for triple digit temps.
I just love warm weather. It reinvigorates me.... Cooler temps wasn't what I couldn't tolerate the most about living in MI. It were those days in which at noon it would be 65 degrees and sunny, but suddenly w/in a span of 6-hours later the temps would drop to around 30 degrees and it would be snowing. It was if as though I traveled from the North to South Pole within a matter of a day. I just couldn't deal with that type of range. A 30-degree drop here is tolerable....the exception though would be during the winter, but those nights are quite rare.