...There is a little sign on the door as you walk into the grocery store explaining to you that the floor may be wet due to rain. I don't know if this is because otherwise people would be wondering why there are dirty wet trails through the entrance area or if it's so that they are covered in case someone tries to sue them after they slip. Either way it's a southern CA thing.
...Your kids go running to the front door yelling, "Look mommy it's RAINING!! Can we go outside in it?"
...You've lived in an apartment for 5 months (Sept. through January) before noticing that there is absolutely no weather stripping under your front door and you finally figured it out because your bare feet were feeling cold one very windy night.
...When all the cars on the freeway start to crawl as soon as the rain hits the windshield because no one knows how to drive in rain. (Also because all of the oil deposits in the grooved concrete start to float up and make it slick but still, it's rain people, I learned to drive on ice.)
...You want to start knitting yourself a sweater but then wonder if you should bother because it will be too warm to wear one by the time you've finished, say in March.
...If you take your out of town guests to the beach in January so they can look at it, but think they're crazy for not wearing a coat and for dipping their toes in the water, afterall, it's winter here and that water is cold, so cold that the surfers and divers out there have WETSUITS ON, and your kids are begging for a sweater.