Autumn happens in California. Seriously it does. We might not get the spectacular colors of the north east United States. Some places do get nippy though, especially in the farther Northern parts of the State and in the mountains. We have mostly evergreen trees rather than the ones that shed their leaves. What is more, is the evergreens are more able to tolerate drought than deciduous trees. This website shows drought tolerant trees of Northern California, most of them are either a variety of Pine, or Oaks.
Drought is part of the natural cycle of California. Media says its the worst since California became a state in 1850. I disagree. What makes it “worst” is the population that lives here using water that was never really meant to be used for other things like Fracking, and water heavy dependent aquaculture and water heavy farming, like rice. Growing up in the Valley, I used to see large fields of rice growing and thought nothing of it, till my Father pointed out how this was not natural. I could understand if we had regular flooding in that area (seasonal) that one could use it to grow rice. But not all the time, as droughts are a regular occurrence in California. As the larger type of seasonal things happen, the “season” over decades of droughts WILL happen. What it requires is more long term thinking of how to use water not just on a year by year basis of seasons, but decade and even Century or a thousand years looking at water usage and water obtaining from rain to snow.
This means not only what we do on the ground, but how we effect the air as well. Frankly we should live always as if we are in a drought to keep water flowing at realistic rates for our population.