I'm 10b, definitely 10b. ...or is that 23?

I'm talking about USDA Zone 10b.  You can find you own garden zone using the interactive map provided by the government.  There's helpful street and satellite map overlays, which I chose not to show below, but it's clear enough once you get to the web site.

Zone 10b has low temperatures in the range 35 to 40 F, so it's supposed to never get below freezing.  That seems about right.  The zone system is a bit simplistic if it's the only criterion that is applied to guide plant purchases. Apparently this is more a problem in the west than the east, since our secondary growing factor is water.

Sunset Magazine takes this and more into account and says I am in Sunset zone 23.

ZONE 23: Thermal belts of Southern California’s coastal climate 
One of the most favored areas in North America for growing subtropical plants, Zone 23 has always been Southern California’s best zone for avocados. Frosts don’t amount to much here, because 85 percent of the time, Pacific Ocean weather dominates; interior air rules only 15 percent of the time. A notorious portion of this 15 percent consists of those days when hot, dry Santa Ana winds blow. Zone 23 lacks either the summer heat or the winter cold necessary to grow pears, most apples, and most peaches. But it enjoys considerably more heat than Zone 24—enough to put the sweetness in ‘Valencia’ oranges, for example—but not enough for ‘Washington’ naval oranges, which are grown farther inland. Temperatures are mild here, but severe winters descend at times. Average lows range from 43 to 48°F (6 to 9°C), while extreme lows average from 34 to 27°F (1 to –3°C).

I'd say they pretty much got it dead to rights.