Hmmm... you live in California? Well, according to the website Californian Frogs and Toads, to me that looks like a Pseudacris hypochondriaca, also known as a Baja California Tree frog. The nose coloration, with the white below the black stripe leading to the eye suggests that it is, as well as the bright green coloration.
I could be wrong. It's either that, or a Pseudacris sierra, also known as a Sierran Tree frog.
Either way, it's a tree frog juvenile or tree froglet.