I'm now pretty sure that it's a brown widow. I saw some pictures of these out there.

So far as I have read, they are not supposed to be in California.

I found another one outside the front door. In both cases, the spiders were out in the open, lying in wait. Not reclusive.

They can be dangerous, so I'll have to watch out for them.

If it is a Brown Widow, Latrodectus geometricus, and that would be my guess--I think they're an import from Australia. I've found these in S. CA and the Mojave Desert going back years. Some say they are recent, but I say not so recent.

If it is a brown widow they are found in CA. See other images and info page here.

Since that picture, I've found four more adults and an egg sack on our gate. There seems to be an infestation. They're also not as reclusive as I thought. One was by the front door, one by the back door, and two were in the garbage can lids.

We used to have black widows, but I have not seen any since we started getting brown widows. I wonder if the browns are somehow replacing the blacks, perhaps by out-competing.

In any case, I don't feel any safer knowing that the brown widows are out in force, even if they have somehow managed to reduce the black widow population. Although I haven't been attacked, they are more assertive in their chosen places of lodging. The black widows never got into the garbage cans.

Some years are just better than others? I've heard that brown widows are less dangerous than black, if that makes you feel any better.