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ZIP 96813 planting calendar

When to plant tomatoes in Honolulu, HI - Zone 12b

In ZIP 96813, plant tomatoes around Jan 8; this uses the Honolulu frost station, USDA zone 12b, and tomatoes timing rules.

Your Honolulu calendar has a 364-day estimated frost-free season. This estimate uses the representative Honolulu frost station, USDA zone 12b, and tomatoes timing rules.

Source: honolulu-intl frost station, USDA zone 12b, last updated 2026-06-28. Verify locally before planting high-value crops because microclimates, current weather, and yard exposure can move the safe date.

USDA zone 12b Honolulu frost station University of Hawaii Cooperative Extension Updated 2026-06-28
Read the method

Answer first

When to start tomatoes seeds indoors in Honolulu

In ZIP 96813, start tomatoes seeds indoors around Nov 20, about 42 days before the Jan 1 last-frost estimate.

Start tomatoes seeds indoors in Honolulu around Nov 20, about 42 days before the Jan 1 last-frost estimate.

Seed starting schedule

Tomatoes dates for Honolulu, HI

StepDateHow to use it
Start IndoorsNovember 20, 2025Start seeds under lights or in a bright indoor seed-starting space.
Transplant OutdoorsJanuary 8, 2026Move hardened-off seedlings outside after the frost-risk window.

Last frost

When is the last frost in Honolulu?

Honolulu (ZIP 96813) has an average last spring frost around Jan 1.

First frost

When is the first frost in Honolulu?

The average first fall frost is around Dec 31, giving about 364 frost-free days.

Season map

Tomatoes windows by month

JanFebMarAprMayJunJulAugSepOctNovDec
Start indoors
Nov 20
Transplant
Jan 8
Harvest
Mar 27
Frost watch
Oct 14

Reminder workflow

Every date has a next action

Start tomatoes indoorsNov 20
Last frost windowJan 1
Transplant tomatoesJan 8
First tomatoes harvest windowMar 27
Last tomatoes sowing targetOct 14
SignalValueWhy it matters
Last frost estimateJanuary 1, 2026Warm-season transplant risk starts falling after this window.
First frost estimateDecember 31, 2026Fall planting counts backward from this date.
Season length364 daysLonger seasons can support succession crops.
Spacing18-24 inAirflow and root space affect yield.
Soil temperature60 F+Seeds and transplants stall in cold soil.

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Local data

Why this date changes by ZIP

Honolulu frost history and USDA zone 12b shift the safe planting window. GrowZone uses a local representative station instead of one national rule.

University of Hawaii Cooperative Extension is the kind of local source to verify against when a crop is expensive, weather is unusual, or your yard has a cold pocket.

Crop note

Tomatoes timing notes

Harden seedlings off for a week before transplanting. Tomatoes prefers full sun, 18-24 in spacing, and soil near 60 F+.

For fall, count backward from Dec 31. A conservative last sowing target is around Oct 14.