Zone 10b Frost Dates & Planting Calendar

What zone 10b actually tells you

The 2023 USDA Plant Hardiness Zone Map puts a place in zone 10b when the coldest night of the year averaged 35 to 40°F (1.7 to 4.4°C) over 1991–2020. The zone says which perennials survive the winter, not when to plant in spring.

Across the 2 NOAA stations behind zone 10b ZIP pages, the median 50% last spring frost is March 4 and the median first fall frost December 15; the last frost alone ranges from January 24 to March 4 from one station to another.

Frost dates answer the planting question, and they are read from the nearest NOAA station, not from the zone. The zone 10b ZIP codes here lie in 5 states; pick your own ZIP code below, or look up the zone of any ZIP code.