Southern California is the main homeless destination in the country. The Los Angeles basin is unusual. It is a bowl of surrounding mountains against a rare deep ocean upwelling current. We actually have fewer really hot Summer days near the coast than you might think. There needs to be a pattern that pulls the desert out over the cold ocean to make the signature SoCal beach days. The rest of the time, within a few miles of the ocean, the temperatures stay quite mild. San Diego gets hot, and just north of LA it gets cold enough to freeze in winter, but not within the basin. It also only rains for a few weeks total every year, and all of that will pretty much happen a week at a time. Up near the center, Sierra mountains are the likely cause.
No joke there are 100k homeless people in the LA basin right now.