Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated

Planting zone for 96746 — Kapaa, HI

ZIP code 96746 (Kapaa, Kauai County) is in USDA zone 12a: the coldest winter night averages 50 to 55 °F.

Where ZIP 96746 is

Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone12a50 to 55 °F
Coldest night10 to 12.8 °C
Last frostrare
First frostrare
2012 zone12a

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 12a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Kapaa, HI…

Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates

A 32 °F frost doesn't happen here in most winters. At the nearest station (NOAA station Kanalohuluhulu 1075, HI — 20 miles away, elevation 3,599 ft) the median growing season is 365 days. When frost does come, it is a midwinter night or two; cover tender plants when a freeze is forecast.

Frost data: NOAA NCEI U.S. Climate Normals 1991–2020.

Native plants for zone 12a in Hawaii

37 plants native to Hawaii, recorded in Hawaii, and rated by the USDA to survive 50 °F or colder — the bottom of zone 12a. Each links to its USDA PLANTS profile.

Trees 7

Chamisso's manfern10 ft · blooms indeterminate · medium shade tolerance · to 40 °Fhapu'u8 ft · blooms indeterminate · medium shade tolerance · to 40 °FHawai'i pritchardia60 ft · medium shade tolerance · to 40 °FKamalo pritchardia16 ft · medium shade tolerance · to 40 °Fkoa110 ft · blooms spring · high shade tolerance · to 31 °Fkoaoha40 ft · blooms early spring · high shade tolerance · to 25 °F

Shrubs 12

'ala'a40 ft · medium shade tolerance · to 40 °F'ohi'a lehua65 ft · blooms late spring · high shade tolerance · to 22 °Fbeach naupaka10 ft · blooms indeterminate · medium shade tolerance · to 31 °FGaudichaud's senna2 ft · to 40 °FHawai'i desert-thorn1 ft · blooms summer · medium shade tolerance · to 40 °FHawai'i hawthorn12 ft · blooms spring · medium shade tolerance · to 35 °F

Wildflowers & perennials 8

bayhops1 ft · blooms indeterminate · medium shade tolerance · to 17 °Fbeach strawberry0.8 ft · blooms early spring · medium shade tolerance · to −33 °Fcommon duckmeatblooms late summer · medium shade tolerance · to −38 °Fcommon maidenhair1.7 ft · blooms summer · low shade tolerance · to −33 °Flongleaf pondweedblooms mid summer · high shade tolerance · to −38 °Fsalt heliotrope1.2 ft · blooms mid spring · high shade tolerance · to −28 °F

Grasses 10

blunt spikerush1.6 ft · blooms summer · high shade tolerance · to 37 °Fcosmopolitan bulrush3 ft · blooms late summer · high shade tolerance · to −23 °Ffragrant flatsedge2 ft · blooms late summer · high shade tolerance · to 42 °Fkawelu3 ft · high shade tolerance · to 40 °Fmanyspike flatsedge1.6 ft · blooms mid summer · high shade tolerance · to 47 °Fovate spikerush1.5 ft · blooms late summer · high shade tolerance · to 47 °F

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in Kapaa, HI.

Soil in Kapaa, HI

The soil mapped at the center of ZIP 96746 is Rough broken land — silty clay loam, well drained.

TextureSilty clay loamholds water and nutrients; slow to drain and warm up
pH5.6moderately acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter6%high
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Rough broken land.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 96746; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Kapaa, HI

Summer high85 °Faverage high, July
Winter low66 °Faverage low, January
Hot days1days a year at 90 °F or more
Freezing nights0nights a year at 32 °F or less
Growing degree days9,599base 50 °F — the season’s usable heat
Longest day13 h 29 mindaylight on June 21
Shortest day10 h 47 mindaylight on December 21
Onions to growShort-daysummer days stay under about 14 h 20 min, so long-day varieties won’t bulb
Precipitation73.8 inper year, rain and melted snow

Average high and low, by month

60°70°80°90°100°January: average high 79 °F, low 66 °F 79°66° JanFebruary: average high 78 °F, low 66 °F 78°66° FebMarch: average high 79 °F, low 67 °F 79°67° MarApril: average high 80 °F, low 70 °F 80°70° AprMay: average high 82 °F, low 71 °F 82°71° MayJune: average high 83 °F, low 73 °F 83°73° JunJuly: average high 85 °F, low 75 °F 85°75° JulAugust: average high 85 °F, low 75 °F 85°75° AugSeptember: average high 85 °F, low 75 °F 85°75° SepOctober: average high 84 °F, low 74 °F 84°74° OctNovember: average high 81 °F, low 71 °F 81°71° NovDecember: average high 79 °F, low 69 °F 79°69° Dec

Precipitation by month inches

0″2″4″6″8″10″January: 4.83 in precipitation 4.8 JanFebruary: 6.47 in precipitation 6.5 FebMarch: 7.89 in precipitation 7.9 MarApril: 5.60 in precipitation 5.6 AprMay: 4.30 in precipitation 4.3 MayJune: 6.01 in precipitation 6.0 JunJuly: 4.28 in precipitation 4.3 JulAugust: 7.12 in precipitation 7.1 AugSeptember: 4.26 in precipitation 4.3 SepOctober: 5.15 in precipitation 5.2 OctNovember: 8.67 in precipitation 8.7 NovDecember: 9.24 in precipitation 9.2 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Lihue WSO Airport 1020.1, HI (7 mi away); precipitation: Kapaa 1.4 W, HI (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

4 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

9675112b
Kealia, HI · 3 mi
9670312a
Anahola, HI · 3 mi
9676612a
Lihue, HI · 7 mi
9671512b
Hanamaulu, HI · 7 mi
9675412b
Kilauea, HI · 7 mi
9672212b
Princeville, HI · 10 mi
9671412a
Hanalei, HI · 11 mi
9674112a
Kalaheo, HI · 14 mi

Hawaii planting zones →

Questions about 96746

What planting zone is ZIP code 96746?

ZIP code 96746 (Kapaa, HI) is in USDA hardiness zone 12a on the 2023 map: the coldest night of an average winter reaches 50 to 55 °F (10 to 12.8 °C).

How much rain and snow does 96746 get?

About 73.8 inches of precipitation a year (NOAA 1991–2020 normals, Kapaa 1.4 W station).

How hot do summers get in Kapaa, HI?

The average high peaks at 85 °F in July, with about 1 days a year at 90 °F or more.

What kind of soil does 96746 have?

The USDA soil survey maps Rough broken land at the center of ZIP 96746: silty clay loam, well drained, pH about 5.6 (moderately acidic).

What kind of onions grow in Kapaa, HI?

Short-day onions: the longest day near 96746 is 13 h 29 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.