Don't forget about micro climates Annette. You likely still are Zone 10B
For myself, much of Vancouver is Zone 8A but at my place, it is Zone 8B-9A. I track my own minimum winter temperatures with my own professional weather station and it is always warmer here than elsewhere in the city. I am only a few feet above sea level and very close to the ocean so I have the moderating influences of the water and a dead air zone with the tree greenbelt next door.
Cheers,
Sean