Urban Honolulu, Hawaii, sits in USDA hardiness zone 12b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
A short list that earns its place here — cassava, starfruit, allspice, and eggplant — with any one site's soil, sun, and drainage making the final cut.
Even in Urban Honolulu, no two yards are alike.
A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Urban Honolulu lot. Enter your address and we'll score 1,086 plants against your land's actual soil, sun, and frost.
We read public map data around Urban Honolulu — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Urban Honolulu — the short answer
Urban Honolulu, Hawaii: USDA zone 12b, no 28°F killing freeze in Honolulu County’s record — the season is year-round, across 39K acres of town.
- USDA zone
- 12b
- USDA PHZM 2023
- Killing freeze
- None on record
- Honolulu County normal — NOAA RCC ACIS 1991–2020, nearest to this town
- Town area
- 39K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. The year-round finding is measured — Honolulu County’s 30-year record, the closest to this town, contains no 28°F killing freeze — never inferred from missing dates.
Hardiness Zone Range
Zone 12b is Urban Honolulu's average, not your lot's — a low corner or a tree line moves it. Against Urban Honolulu's no killing freeze on record, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Urban Honolulu
Each reading below is measured for Urban Honolulu itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsUrban Honolulu has no station of its own, and Honolulu County’s 30-year record — the closest to it — carries no 28°F killing freeze at all — year-round growing.
Frost is rarely the limit here; winter plantings are as real as summer ones, and the harder question is which crops shrug off the summer heat.
Grow cool-season crops through the mild winter, and choose heat-tolerant varieties for the summer beds.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredUrban Honolulu sits in USDA hardiness zone 12b.
The zone sets which perennials, shrubs, and fruit trees live through an average winter here — a plant rated for a colder zone is a safe bet, one rated warmer needs winter protection or gets treated as an annual.
Match perennials and fruit to the zone before you buy, so nothing you plant is a gamble against the cold.
USDA PHZM 2023
What Grows in Urban Honolulu
Every plant below cleared Urban Honolulu's own zone 12b and its 365-day season. Each card opens that plant's Hawaii profile. How we score.
What's on the federal record near Urban Honolulu
Closest first, within ~10 miles of Urban Honolulu. Listing isn't leaking, and distance isn't exposure.
- HONOLULU SAKE BREWERY CO, LTDUnderground Storage Tanks · 1200 ft
- NUUANU FIRE STATION #25Underground Storage Tanks · 1400 ft
- PACIFIC HEIGHTS SHELLUnderground Storage Tanks · 1700 ft
- PACIFIC HEIGHTS SHELLBrownfields · 1700 ft
- PUUNUI CENTRAL OFFICEUnderground Storage Tanks · 1900 ft
- PEARL HARBOR OIL SPILL DRILLBrownfields · 2000 ft
- IES Retail NuuanuUnderground Storage Tanks · 2100 ft
- HAWAII MEDICAL CENTER EASTBrownfields · 2100 ft
- HAWAII CANCER CENTER LILIHA CLINICBrownfields · 2100 ft
- SAINT FRANCIS HOSPITALUnderground Storage Tanks · 2300 ft
- REHAB HOSPITAL OF THE PACIFICUnderground Storage Tanks · 2600 ft
- MALULANI HALEUnderground Storage Tanks · 0.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Urban Honolulu's center, not your beds. Run your own address for what's upwind of you specifically.
Environmental Intelligence
The counts behind that headline — every source type on the record near Urban Honolulu.
Total Sites
1,909
within ~10 miles of Urban Honolulu
Risk Level
Elevated
Highest-severity
38 Superfund sites
Sources Checked
within ~10 miles of Urban Honolulu
Severity Distribution
within ~10 miles of Urban Honolulu
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Urban Honolulu, Superfund runs higher than the national average — 38 sites within ~10 miles of Urban Honolulu. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check your specific parcel in Urban Honolulu
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,086 plant recommendations.
25+ data sources read at your address, not the Urban Honolulu average
Your land is one point inside Urban Honolulu
Everything above resolves to Urban Honolulu as a whole — one PHZM band, read across 39K acres, with hard-freeze dates borrowed from Honolulu County’s record because no 30-year normal resolves at this town’s own centroid. Your parcel is one point inside that footprint. Slope, tree cover, a low spot that pools cold air, and what is in the soil are all resolved at the address, and none of them are visible at town scale. That is the honest boundary of this page, and the reason the next step is a reading of your own ground rather than a better local average.
Your Lot vs the Urban Honolulu Average
Urban Honolulu Average
- ●USDA Zones 12b, averaged across Urban Honolulu
- ●One soil character for all of Urban Honolulu
- ●State-average frost dates
YOUR Parcel
- ✓Your exact zone, not Urban Honolulu's 12b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Urban Honolulu
Pull a site-specific report for your exact address in Urban Honolulu, Hawaii — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Urban Honolulu averages can't show:
We read public map data around Urban Honolulu — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Urban Honolulu average
How we know this about Urban Honolulu
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Honolulu County’s record, because none resolves here; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at town grain anywhere on this page — there is no town-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.
Common questions about Urban Honolulu
Is it too late to plant in Urban Honolulu?
No — Urban Honolulu has no station of its own, and Honolulu County's 30-year record, the closest to it, holds no 28°F killing freeze, so the growing season is year-round and there is no last-frost date to wait for. Planting is paced by rainfall, heat and daylength instead of by frost: start heat-lovers any month, and time cool-season crops (lettuce, brassicas, peas) for the cooler, wetter half of the year or for higher ground. Succession sowing every few weeks works all year, so the limit is what you can keep watered and harvested, not the calendar.
When does frost risk typically end in Urban Honolulu?
It doesn't — Urban Honolulu has no station of its own, and the 1991–2020 record for Honolulu County, the nearest to it, carries no 28°F killing freeze at all, so there is no spring frost date to plant after. Cold still matters with elevation: the higher you garden, the cooler the nights, and a few tropical crops sulk below about 60°F even where they never freeze.
How long is the growing season in Urban Honolulu?
Year-round — Urban Honolulu has no station of its own, and the 1991–2020 record for Honolulu County, the closest to it, contains no 28°F killing freeze, so there is no season to measure between freezes. What paces planting instead is heat, rainfall and daylength: the hottest, wettest stretch is the hard part for cool-season crops, not winter. Elevation is the one real exception — the higher you garden, the colder the nights get.
Is the soil safe to grow vegetables in Urban Honolulu?
The federal record around Urban Honolulu is a meaningful one — 1,909 documented sites, mostly Underground Storage Tanks entries (1,150), the nearest Underground Storage Tanks record about 0.2 miles out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
Everything above is measured at Urban Honolulu's scale — its 12b band and its no killing freeze on record. Your yard writes its own version of Urban Honolulu's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
What this page reads at Urban Honolulu’s own scale
4 of the readings below were taken at Urban Honolulu's own scale — the 38,798 acres it covers and 1,909 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Urban Honolulu's own USDA hardiness band, zones 12bUSDA PHZM 2023
- 1,909 documented contamination sites on the federal record near Urban Honolulu, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Urban Honolulu's boundary and the 38,798 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 12b and a ~365-day seasonGrowable Ground crop-matching engine
Inherited from a wider read
- The frost finding — Urban Honolulu has no station of its own, and its county's 30-year record contains no 28°F killing freeze at allfrom Honolulu County
- Soil character — no town-scale survey exists, so Urban Honolulu's 38,798 acres read through its county's SSURGO summaryfrom Honolulu County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Honolulu County
- The growing challenges every Hawaii grower plans around — written at state scale, so they stay on the state guidefrom Hawaii
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Honolulu County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Urban Honolulu's 38,798 acreswhy one lot differs from the next →
- Which side of Urban Honolulu you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 38,798 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.2 miles out, measured from the town centrehow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any Urban Honolulu-wide figureread your own land →
More in Hawaii
Wider growing context
What grows across HawaiiUrban Honolulu sits outside our named growing regions, so Hawaii as a whole is its closest context here.
Nearby growing guides