In SoCal, climate zone 10, and even peach trees that you'll occasionally see in people's yards (Babcock, I'm assuming) don't seem to produce well here. I've only ever come across one apple tree with fruits, and they were very little apples.
But I did find this:
The latest reports have shown that apples tend to be more adaptable to lower-chill areas than was previously thought. A field test by Tom Spellman of Dave Wilson Nursery showed that several apple varieties rated for 800 chill hours could grow just fine in Irvine (located in coastal Southern California, which only gets 50-100 real chill hours). The following apple varieties did surprisingly well: King Tompkins, Braeburn, Gravenstein, Cox's Orange Pippin. The trees tended to flower and set fruit throughout the year rather than a specific season.
https://www.youtube.com/watch?v=oiEEHRfAEWYThe results might have had something to do with the fact that the coastal influence has a moderating effect on temperature, and in the winter it rarely ever gets above 65 F in this region, higher temperatures being very detrimental to effective chill accumulation. In other words, the same moderating influence that prevents there from ever being any chill hours below 45 F may be, paradoxically, the same influence that allows the trees to grow well even in the absence of chill hours below 45 F.