Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 96749 — Keaau, HI

ZIP code 96749 (Keaau, Hawaii County) is in USDA zone 12b: the coldest winter night averages 55 to 60 °F. The median last spring frost is April 12 and the first fall frost December 1.

Where ZIP 96749 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.

Zone12b55 to 60 °F

Coldest night12.8 to 15.6 °C

Last frostApr 12

First frostDec 1

2012 zone12b

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 12b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Keaau, 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 in Keaau, HI

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostApril 12median — 50% chance of a later frost

Safe for tender plantsMay 18only 10% chance of frost after

First fall frostDecember 1median — 10% chance by Nov 9

Growing season235 daysfrost-free, median

A hard freeze (28 °F) usually ends around February 13 and returns around January 22.

From the NOAA station Mauna Loa 5 Nne, HI — 39 miles away, elevation 11,178 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in 96749

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 1 – Mar 15

SpinachSow outdoors · Mar 1 – Mar 22

Broccoli, cabbageStart indoors · Feb 1 – Feb 15

Broccoli, cabbageTransplant · Mar 22 – Apr 5

Onion setsPlant outdoors · Mar 15 – Mar 29

PotatoesPlant outdoors · Mar 22 – Apr 5

LettuceSow outdoors · Mar 15 – Mar 29

Carrots, beetsSow outdoors · Mar 22 – Apr 5

TomatoesStart indoors · Feb 15 – Mar 1

TomatoesTransplant · Apr 19 – May 3

Peppers, eggplantStart indoors · Feb 1 – Feb 15

Peppers, eggplantTransplant · Apr 26 – May 10

BeansSow outdoors · Apr 19 – May 3

Sweet cornSow outdoors · Apr 19 – May 3

Cucumbers, squashSow outdoors · Apr 19 – May 3

Fall lettuce, spinachSow outdoors · Oct 6 – Oct 20

GarlicPlant cloves · Nov 17 – Dec 22

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 12) and first fall frost (Dec 1) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

Soil in Keaau, HI

The soil mapped at the center of ZIP 96749 is Keaukaha — highly decomposed plant material, well drained.

TextureHighly decomposed plant materialtop layer

pH5.3strongly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter60%high

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Keaukaha highly decomposed plant material, 2 to 10 percent slopes.

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 96749; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Keaau, HI

Summer high80 °Faverage high, August

Winter low61 °Faverage low, January

Hot days0days a year at 90 °F or more

Freezing nights0nights a year at 32 °F or less

Growing degree days7,536base 50 °F — the season’s usable heat

Longest day13 h 19 mindaylight on June 21

Shortest day10 h 57 mindaylight on December 21

Onions to growShort-daysummer days stay under about 14 h 20 min, so long-day varieties won’t bulb

Precipitation151.2 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Hilo 5 S, HI (6 mi away); precipitation: Hilo 5 S, HI (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

9676012a

Kurtistown, HI · 6 mi

9672112b

Hilo, HI · 10 mi

9677111b

Mountain View, HI · 14 mi

Hawaii planting zones →

Questions about 96749

What planting zone is ZIP code 96749?

ZIP code 96749 (Keaau, HI) is in USDA hardiness zone 12b on the 2023 map: the coldest night of an average winter reaches 55 to 60 °F (12.8 to 15.6 °C).

When is the last frost in Keaau, HI?

The median last spring frost (32 °F) near 96749 is April 12; after May 18 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Mauna Loa 5 Nne station.

When is the first frost in Keaau, HI?

The median first fall frost near 96749 is December 1, giving a median frost-free growing season of 235 days.

When should I plant tomatoes in 96749?

Start tomato seeds indoors around Feb 15 – Mar 1 and set transplants outside around Apr 19 – May 3, one to three weeks after the median last frost.

How much rain and snow does 96749 get?

About 151.2 inches of precipitation a year (NOAA 1991–2020 normals, Hilo 5 S station).

How hot do summers get in Keaau, HI?

The average high peaks at 80 °F in August, with about 0 days a year at 90 °F or more.

What kind of soil does 96749 have?

The USDA soil survey maps Keaukaha at the center of ZIP 96749: highly decomposed plant material, well drained, pH about 5.3 (strongly acidic).

What kind of onions grow in Keaau, HI?

Short-day onions: the longest day near 96749 is 13 h 19 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.