Zone 9a Frost Dates & Planting Calendar

What zone 9a actually tells you

The 2023 USDA Plant Hardiness Zone Map puts a place in zone 9a when the coldest night of the year averaged 20 to 25°F (-6.7 to -3.9°C) over 1991–2020. The zone says which perennials survive the winter, not when to plant in spring.

Across the 363 NOAA stations behind zone 9a ZIP pages, the median 50% last spring frost is March 3 and the median first fall frost November 25; the last frost alone ranges from January 20 to June 1 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 9a ZIP codes here lie in 16 states; pick your own ZIP code below, or look up the zone of any ZIP code.