cali has like the highest number of applicants and the lowest proportional number of spots (of states with medical schools). all things being equal, someone in PA applying to an in-state school faces less competition than someone in CA applying to an in-state school. so as a cali resident you face higher in-state competition.
also, some factors exacerbate the national demand for those spots, and so you also face considerably more out of state competition than most other schools in the nation: most med schools in cali are public and therefore cheaper; awesome lifestyle (culture, weather, etc); high demand for physicians even in non-medical fields, like pharma; and there arent any bad schools in cali, as there are in some other states (ie, ive seen some people smirk when someone introduces themselves as an MS at drexel; on the other hand, no one smirks if one introduces theirself as an MS at uci).
these make demand for california spots incredibly high and push up the stats necessary to get in. if you are from cali always apply to out of state schools just in case.