Phidippus johnsoni ?
Hi, and welcome to the site. Your spider is one of the jumping spiders in the Salticidae family,This one is in the genus Phidippus, in the johnsoni group called red backed jumpers or johnson jumpers.
They are not dangerous at all, a bite might compare to an ant sting or mild bee sting.
Thanks, Dan. That’s what I thought after looking at other photos. Quite pretty and probably was a female. Seems others in Northern CA have spotted some of these.
You are welcome, sorry I can’t suggest a gender from the photo.