As is often the case, Wikipedia gives a very accessible, easy to use article:
http://en.wikipedia.org/wiki/K...
I found that my Koppen climate classification is Csb, "Dry-summer subtropical or Mediterranean climate" .
"These climates ... have moderate temperatures and changeable, rainy weather. Summers are hot and dry... except in the immediate coastal areas, where summers are milder due to the nearby presence of cold ocean currents that may bring fog but prevent rain."