Place guide
Planting zones in Kahului-Wailuku, HI
This metro spans USDA zones 11b to 12b, so there is no single zone for Kahului-Wailuku, HI and anyone who gives you one is rounding. 67% of its ZIP codes are zone 12b; the rest are not.
Your ZIP code
Get the exact answer for your address
Everything above describes Kahului-Wailuku, HI as a whole. Hardiness zones and freeze dates are published per ZIP code, so yours is exact — enter it and this page will tell you your zone, which NOAA station it comes from and how far away that station is.
What you can sow in Kahului-Wailuku, HI now
32 of 32 crops that every one of the 9 NOAA stations serving this metro area agrees still has time to mature — with a week in hand, so this holds until the page is next rebuilt.
- 🌱 Radishes 28d
- 🥬 Arugula 35d
- 🥬 Baby Salad Greens 35d
- 🥬 Spinach 40d
- 🥬 Mustard Greens 40d
- 🥬 Leaf Lettuce 45d
- 🌿 Cilantro 45d
- 🥬 Bok Choy 45d
- 🌿 Dill 45d
- 🥔 Turnips 50d
- 🧅 Green Onions 55d
- 🥬 Swiss Chard 55d
- 🫘 Bush Beans 55d
- 🥬 Kohlrabi 55d
- 🥒 Zucchini 55d
- 🎃 Summer Squash 55d
- 🌶️ Okra 55d
- 🥕 Beets 58d
- 🥬 Kale 60d
- 🥬 Collards 60d
- 🥒 Cucumbers 60d
- 🫛 Peas 65d
- 🫘 Southern Peas 65d
- 🥕 Carrots 70d
- 🌽 Sweet Corn 75d
- 🎃 Winter Squash 95d
- 🎃 Pumpkins 100d
- 🥦 Broccoli 60d
- 🍅 Tomatoes 60d
- 🌶️ Peppers 65d
- 🥬 Cabbage 70d
- 🍠 Sweet Potato 100d
No station serving this metro area records a freeze at any probability, so frost is not what limits the list — heat and day length are.
No station serving this metro area records a freeze at any probability, so there is no season boundary to draw — the growing season here is the whole year.
Which zone you are in depends where you are
Kahului-Wailuku, HI covers 3 hardiness zones. A guide that gives the metro one zone has picked whichever is largest and rounded everyone else into it — which is fine for the 67% in zone 12b and wrong for the other 33%. Here is the actual split.
| Zone | ZIP codes | Share | |
|---|---|---|---|
| 12b | 10 | 67% | |
| 12a | 4 | 27% | |
| 11b | 1 | 7% |
Zones are published per ZIP code, so yours is exact even though the metro's is not. The hardiness tool will tell you which one you are in.
Your freeze dates
No freeze range is shown for Kahului-Wailuku, HI, because at least one station here records no freeze at any probability, so there is no date to average. The tools below still answer for individual ZIP codes here, and will say what applies.
Your growing season
NOAA publishes a growing-season length for each station, and across the 9 stations serving Kahului-Wailuku, HI it runs 365 days . That figure is published, not computed from the two freeze dates — subtracting one from the other gives the wrong answer wherever a season crosses New Year. Mean summer high (June–August) runs 66–89 °F , below the 90 °F point where cool-season crops reliably bolt. Summer rain over the same months runs 1.2–18.8" across those 8 stations, against the rough inch a week — about 13 inches over the same 92 days — that a vegetable garden is usually reckoned to want. The middle station covers about 24% of it, so a summer garden here is watered rather than rained on. The inches are NOAA's published normals; the inch a week is a rule of thumb, and it takes no account of a 83 °F summer afternoon drying the soil faster than a cool one.
What survives the winter changes across Kahului-Wailuku, HI
Of 74 perennial fruits, nuts, berries, vegetables and herbs, 18 come through the winter in zone 11b and only 14 in zone 12a. That is a different garden at each end of the same metro.
| Zone | ZIPs | Survive | Fail for being too warm |
|---|---|---|---|
| 11b | 1 | 18 of 74 | 56 |
| 12a | 4 | 14 of 74 | 60 |
| 12b | 10 | 14 of 74 | 60 |
The last column is the counterintuitive one, and it is why the totals do not simply rise as the winters get milder. Most temperate fruit needs a documented number of hours below about 45 °F to break dormancy and set a crop, so an apple fails in a winter that is too warm; currants and rhubarb cook in the summer heat that comes with it. See the full list with reasons.
With no freeze recorded at any probability, there are no dates to be uncertain about — the question this chart answers does not arise here.
The 9 stations behind these numbers
All 9 NOAA stations whose normals this page quotes, spanning about 55 km north to south. Every one is named with its identifier in the station list below — this page does not single one out, because no one station speaks for a whole metro area.
A relative sketch, not a map with a projection: longitude is adjusted for latitude so the shape is not stretched, and there is no basemap. For the one station nearest a specific address, with its real distance, use the ZIP lookup above.
Every figure above comes from these, and each is named so you can check it. Which station serves a given ZIP code, and how far away it is, varies across the metro — the table below gives it per ZIP code rather than this page averaging it.
| Station | NOAA ID | Last spring freeze | First fall freeze | Season |
|---|---|---|---|---|
| Haleakala RS 338, HI | USC00511004 | no freeze recorded | no freeze recorded | 365 days |
| Kahului AP, HI | USW00022516 | no freeze recorded | no freeze recorded | 365 days |
| Kula Branch Stn 324.5, HI | USC00515000 | no freeze recorded | no freeze recorded | 365 days |
| Kula Hospital 267, HI | USC00515004 | no freeze recorded | no freeze recorded | 365 days |
| Lanai AP 656, HI | USC00515275 | no freeze recorded | no freeze recorded | 365 days |
| Molokai AP, HI | USW00022534 | no freeze recorded | no freeze recorded | 365 days |
| Ohe'O 258.6, HI | USC00517000 | no freeze recorded | no freeze recorded | 365 days |
| Puu-O-Hoku Rch 542.1, HI | USC00518549 | no freeze recorded | no freeze recorded | 365 days |
| Puukolii 457.1, HI | USC00518407 | no freeze recorded | no freeze recorded | 365 days |
These are medians, not averages — NOAA publishes freeze dates as a probability distribution, and half of years freeze later than the date shown.
Every ZIP code in Kahului-Wailuku, HI
Zones are published per ZIP code, not per metro area, so this is the exact answer rather than the metro area's average. The station column is the nearest one to that ZIP code's centroid and how far away it is — the same figure the tools use, shown here so you can see which ZIP codes are well covered and which are reaching.
| ZIP code | USDA zone | Nearest NOAA station | Distance |
|---|---|---|---|
| 96708 | 12a | Haleakala RS 338, HI | 13.7 km |
| 96713 | 11b | Ohe'O 258.6, HI | 10.4 km |
| 96729 | 12b | Molokai AP, HI | 3.6 km |
| 96732 | 12b | Kahului AP, HI | 4.1 km |
| 96742 | 12b | Molokai AP, HI | 13.7 km |
| 96748 | 12b | Puu-O-Hoku Rch 542.1, HI | 10.7 km |
| 96753 | 12b | Kula Hospital 267, HI | 9.3 km |
| 96757 | 12a | Molokai AP, HI | 12.3 km |
| 96761 | 12b | Puukolii 457.1, HI | 6.0 km |
| 96763 | 12b | Lanai AP 656, HI | 5.7 km |
| 96768 | 12a | Kula Branch Stn 324.5, HI | 8.3 km |
| 96770 | 12b | Molokai AP, HI | 12.1 km |
| 96779 | 12b | Kahului AP, HI | 4.7 km |
| 96790 | 12a | Kula Branch Stn 324.5, HI | 5.9 km |
| 96793 | 12b | Kahului AP, HI | 10.5 km |
ZIP-code positions are area centroids, so a large rural ZIP code's listed distance is measured from the middle of its area rather than from any particular address in it.
Your own ZIP
Work out your own dates
Each of these takes a ZIP code and answers for that ZIP alone, citing the station it used and how far away it is. There is a ZIP box in the header of every page.
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What survives my winter?
Runs on the hardiness zone, so it answers for all of Kahului-Wailuku, HI at once — zone across 74 perennial fruits, berries, vegetables and herbs.
- When do I start my seeds?
Dates every spring job from your own last freeze — sow indoors, set out, direct sow.
- When do I sow the next round?
How often each crop is worth re-sowing, and when the next sowing is due.
- What can I still plant?
Counts the growing days left before your first fall freeze, crop by crop.
Other places to compare
Gardening in Hawaii — zones 10b– 13a covers the whole state: how its 96 ZIP codes divide between 6 hardiness zones, and the freeze dates across every NOAA station in it.
Other metro areas in HI:
- Urban Honolulu, HI Zones 12a–13a
Gear
If you want to act on this
Each link opens an Amazon search rather than a product we picked. We have not tested these and do not rank them — the search is the honest version, and you choose.
- Soaker hose and drip kitsThe stations here publish no ordinary freeze window, so frost is not what limits the season — water is, through a summer that does not stop.
As an Amazon Associate we earn from qualifying purchases. That costs you nothing extra, and it buys no influence over anything on this site: the dates come from NOAA normals and the zones from the USDA, and no product affects either.
Sources
Where these numbers come from
The hardiness zone is the USDA 2023 Plant Hardiness Zone Map, published per ZIP code by PRISM at Oregon State. The freeze dates are NOAA's 1991–2020 Climate Normals, read from every station whose normals cover a ZIP code in this metro. Nothing here is estimated, and no station stands in for another.
This page names no single station on purpose. Picking one to represent a metro sounds reasonable and is not: the station serving the most ZIP codes is an artifact of where ZIP centroids happen to fall, and it selects a lock on the Monongahela for Pittsburgh and a far southern suburb for Chicago. A range across every station is true; a single cited date for a whole metro is not.