USDA Plant Hardiness Zone
Zone 11a Frost Dates & Planting Calendar
205 ZIP codes are in zone 11a in the ZIP-code listing of the 2023 USDA Plant Hardiness Zone Map; 110 of them have a frost-date page here.
- Zone
- 11a
- Coldest night, average
- 40 to 45°F
- Median Growing Season
- —
- ZIP codes in the listing
- 205
4.4 to 7.2°C
What zone 11a actually tells you
The 2023 USDA Plant Hardiness Zone Map puts a place in zone 11a when the coldest night of the year averaged 40 to 45°F (4.4 to 7.2°C) over 1991–2020. The zone says which perennials survive the winter, not when to plant in spring.
Frost dates answer the planting question, and they are read from the nearest NOAA station, not from the zone. The zone 11a ZIP codes here lie in 3 states; pick your own ZIP code below, or look up the zone of any ZIP code.
Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.