This spider is a Neriene digna, found in the Western U.S., Canada and Alaska. It belongs to a family called Sheetweb Spiders (Linyphiinae), whose webs can be flat, domed, or bowl-shaped. I have seen domed webs in my yard, with the spider hanging upside-down inside the high point of the dome.
This little guy has been hanging out under the lid of my yard trimmings bin, and it's probably trying to over-winter there in a protected place. There is no web nearby.