It is not completely true that there is no snow in California at all, but in some of the southern part, like Los Angeles, there was no snow in half a century. Some northern parts, like Lake Tahoe, Yosemite Valley, Yuba River, or Kings Beach gets a full load of snow during the winter.
Most of the southern parts are using irrigation and, without that, many places would look like a desert. Without that system that is importing water, many cities, especially Los Angeles, would quickly look like Sahara.
When we speak about snow in the mountains in California, there are high amounts of it there. But, coastal parts like San Francisco, Los Angeles, and San Diego do not get snow at all. Because of the hot climate and the Pacific Ocean, these cities have only twenty days of cold days per year.
The only usual climate for winter there is rain, heavy rain. The main reason for that is tropical water from Hawaii. California is not all strands and pretty exempt people. There are large hills and plenty of normal working class people. In places like that, it is normal at it snowing during the winter.
There is a record that says that the last time when there was snowing in Los Angeles is 54 years ago. Of course, the snow has regularly been unusual on the coastal valleys of Southern California. Los Angeles today is approximately five degrees Fahrenheit hotter than it was a century before. We can assign nearly half that raise to the urban heat island effect – synthetic soil surfaces lifting up more thermal energy than a direct ground cover.
With the progression of global warming all around the world, places with high temperatures are getting harder and harder for living. One of the samples is constant fires in California. So, the conclusion is that most of the places in California will get an even smaller amount of snow in time.