It's pretty easy to check out the latitudes of any particular location using the USGS Recent Earthquakes zoomed in map. Just click on any location, and the resulting map shows latitudes. Using that, it appears that the mid-point latitude is actually just north of Hollister, not too far south of San Jose. Gilroy is almost certainly in the southern half of the state. Not sure where Mary Maya lives, but her latitude as given is so close to that mid-line that it's too close to call. My measurements could be off by a tenth of a degree or two. Glen, your division of the state into thirds caused me to re-check my own calculations, and I'm mortified to find that I'm not really in "Central California" at all. Arroyo Grande is just south of Central California, and thus is in Southern California, unless we all can stipulate that we will henceforth divide the state into quarters, or fifths. Rats.

Mike Williams in Arroyo Grande, CA