USDA hardiness zone
Zone 12a
Rolled up from the 31 ZIP codes in our data that are classified zone 12a, covering 27 nurseries and garden centers across 6 cities we track in this zone.
Average minimum winter temperature
50°F
Frost
Frost is rare or absent across most of this zone; timing here follows temperature, not a spring/fall frost date. Any single ZIP's own exact frost status is on that ZIP's own lookup page, not approximated here.
Average frost-free growing season
363 days
Average monthly temperature
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 56.1° | 56.2° | 57.3° | 59.2° | 60.2° | 62.8° | 64.1° | 64.8° | 63.9° | 63° | 60.6° | 58.4° |
NOAA 1991–2020 Climate Normals, averaged across this zone's member ZIPs.
Crops by frost hardiness
What grows here, and when
Frost is rare or absent here, so cool-season (hardy/semi-hardy) crops typically go in during the cooler months and warm-season (tender/very-tender) crops before the hottest months arrive, rather than on a frost-relative schedule.
Planting windows and crop timing here are computed from USDA/NOAA climate data and the university extension sources cited below, not a site visit or soil test. Treat this as a starting point: local conditions vary, and a local nursery or extension office can advise on your exact site. See our full Disclaimer.
Hardy (49)
- Apple (bare-root fruit tree)
- Apricot (bare-root fruit tree)
- Asparagus
- Bachelor's Button (Cornflower)
- Bare-root rose
- Blackberry
- Blueberry
- Broccoli
- Brussels Sprouts
- Cabbage
- Calendula
- Catnip/Catmint
- Cherry (sweet/tart, bare-root fruit tree)
- Chives
- Collards
- Currant
- Deciduous shade tree (generic, e.g. maple/oak, bare-root or B&B)
- Elderberry
- Evergreen shrub (B&B/potted, e.g. arborvitae, boxwood)
- Flowering deciduous shrub (generic, e.g. lilac/forsythia)
- Garden Peas
- Garlic
- Gooseberry
- Kale
- Kohlrabi
- Larkspur
- Lavender
- Lettuce
- Mint
- Onion (bulb)
- Oregano
- Peach (bare-root fruit tree)
- Pear (bare-root fruit tree)
- Plum (bare-root fruit tree)
- Radish
- Raspberry
- Rhubarb
- Rutabaga
- Sage
- Snapdragon
- Snow Peas
- Spinach
- Strawberry
- Sweet Alyssum
- Sweet Pea
- Table/Bunch Grape
- Tarragon
- Thyme
- Turnip
Semi-hardy (16)
Tender (20)
Zone 12a means an average annual extreme minimum winter temperature of 50°F to 55°F on the 2023 USDA Plant Hardiness Zone Map (USDA/ARS with the PRISM Climate Group at Oregon State University, 1991-2020 records). Every ZIP here carries its zone matched by centroid against the map, not by its polygon boundary, through phzmapi.org's ZIP-level derivation.
We hold no matched NOAA frost station for any of zone 12a's own ZIPs, so there is no last- or first-frost date to report here, only the growing-season figure shown above. Frost isn't rare in this zone; it's outside the range this stretch of NOAA's Hawaii station network is built to record at this elevation and latitude.
We track nurseries across zone 12a, all in Hawaii, with Mililani carrying the most, followed by Aiea and Pearl City.
Cities we track in zone 12a
- Mililani, HI (7)
- Aiea, HI (6)
- Pearl City, HI (6)
- Waipahu, HI (6)
- Kunia Camp, HI (1)
- Wahiawa, HI (1)
Nearby zones
All zones
USDA 2023 Plant Hardiness Zone Map (zone boundaries, via the phzmapi.org ZIP-level derivation) and NOAA 1991–2020 Climate Normals (frost dates, growing season, monthly temperatures).