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

Planting zone for 96859 — Tripler Army Medical Center, HI

ZIP code 96859 (Tripler Army Medical Center, Honolulu County) is in USDA zone 12b: the coldest winter night averages 55 to 60 °F.

Where ZIP 96859 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 frostrare

First frostrare

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 Tripler Army Medical Center, 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

Frost is rare or absent here: Tripler Army Medical Center, HI is in zone 12b, where the coldest night of a typical winter stays above freezing. Cool-season vegetables grow best from fall through spring; summer heat, not frost, is the limit.

Soil in Tripler Army Medical Center, HI

The soil mapped at the center of ZIP 96859 is Manana — silty clay, well drained.

TextureSilty clayholds water and nutrients; slow to drain and warm up

pH5.0strongly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter4.5%moderate

Hydrologic groupCwater soaks in slowly

Farmland classPrime farmland if irrigatedUSDA classification

Map unit: Manana silty clay, 8 to 15 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 96859; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Tripler Army Medical Center, HI

Summer high89 °Faverage high, August

Winter low67 °Faverage low, January

Hot days32days a year at 90 °F or more

Freezing nights0nights a year at 32 °F or less

Growing degree days10,242base 50 °F — the season’s usable heat

Longest day13 h 26 mindaylight on June 21

Shortest day10 h 50 mindaylight on December 21

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

Precipitation31.8 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: Honolulu Intl Airport, HI (4 mi away); precipitation: Moanalua 770, HI (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

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

Hawaii planting zones →

Questions about 96859

What planting zone is ZIP code 96859?

ZIP code 96859 (Tripler Army Medical Center, 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).

How much rain and snow does 96859 get?

About 31.8 inches of precipitation a year (NOAA 1991–2020 normals, Moanalua 770 station).

How hot do summers get in Tripler Army Medical Center, HI?

The average high peaks at 89 °F in August, with about 32 days a year at 90 °F or more.

What kind of soil does 96859 have?

The USDA soil survey maps Manana at the center of ZIP 96859: silty clay, well drained, pH about 5.0 (strongly acidic).

What kind of onions grow in Tripler Army Medical Center, HI?

Short-day onions: the longest day near 96859 is 13 h 26 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.