Southern California is traditionally defined as the 10 counties of San Bernadino, Riverside, Imperial, San Diego, Orange, Los Angeles, Ventura, Santa Barbara, San Luis Obispo, and Kern



If you check the maps of fans and click on San Luis Obispo county you'll find it is 28% Dodgers, 27% Giants, and 11% Angels. This is pretty much the middle ground between north and south, though it has a slight tilt south. (Tulare tilts slightly north, Inyo tilts slightly south on the north side of the N/S line)

https://www.nytimes.com/interactive/2014...9,-118.989

Cal Poly is titled slightly SoCal over NorCal, but basically a toss up. From a driving perspective, Paseo Robles is the exact middle point, 2 hours from the Bay Area and 2 hours from Los Angeles. It is also on the Salinas River which runs north with commerce up to Salinas and Monterey. Anyway San Luis Obispo is the county were north and south meet culturally. I would not call SLO NorCal, it's SoCal, but it's very much borderland.

There is a 3rd California, north of Northern California, which is "Jefferson" (or Del Norte, taking the northern most county). You can define it as everything north of the counties of Sonoma, Napa, Yolo, and Placer. Or put another way, north of the north bay wine country, UC Davis, and I-80 up to Tahoe. It is more similar to Oregon than to California in many ways. It would not surprise anyone if it eventually broke away and formed a new state (large on the map, but probably only two congressional seats).

Anyway that is a geographic primer on California.