Will the evergreen magnolia, Michelia wilsonii, grow in Danville, CA?
It is suitable for your area in Danville (according to the Sunset Western Garden Book). As far as surviving the full sun in your hottest summers, you might want to check with a local nursery about that to be quite sure. The Sunset book says it needs partial shade in the hottest climates [that it grows in], and your Sunset zone appears to be 9, which suggests it has high summer temperatures. It may need to be planted where it will get partial shade.