USDA Plant Hardiness Zone
Zone 10b Frost Dates & Planting Calendar
468 ZIP codes across 5 states fall in zone 10b.
- Zone
- 10b
- Average Annual Low
- 35 to 40°F
- Typical Growing Season
- 356 days
- ZIP Codes
- 468
What zone 10b actually tells you
A hardiness zone describes one thing: the average coldest night of the year, which in zone 10b falls between 35 to 40°F. It answers whether a perennial will survive the winter — not when to plant in spring.
Frost dates answer the planting question, and they vary widely inside a single zone. Zone 10b spans 5 states, and a coastal ZIP can differ from an inland one by three weeks despite sharing the zone. Pick your own ZIP code below rather than planting by zone alone.