Pseudacris sierra, Sierran Treefrog
This little frog has been called a bunch of names.
Pseudacris sierra - Sierran Treefrog or Pacific treefrog, Hyla regilla, or Pseudacris regilla, Pacific Chorus Frog, take your pick.
This form lives in most of California that is not the desert.
They need clean habitat with either heavy morning dew or a moist are. They'll live in some weird places, like among the Chamise hanging upside down sipping the dew as it runs down the stems and their body.
They do very poorly in weeds.