When should I plant tomatoes in ZIP 53202?

In ZIP 53202, the main tomatoes target is around May 17, based on the representative Milwaukee frost station and USDA zone 6a.

When should I start tomatoes seeds indoors in 53202?

Start tomatoes seeds indoors in ZIP 53202 around Mar 29, about 42 days before the May 10 last-frost estimate.

Is this a guaranteed planting date?

No. GrowZone uses frost-date estimates, hardiness zones, and crop timing rules for planning. Local microclimates and current weather can shift the right date.

ZIP 53202 planting calendar

When to plant tomatoes in Milwaukee, WI - Zone 6a

Q: When is the first frost in Milwaukee?

Milwaukee (ZIP 53202) has an average first fall frost around Oct 10, leaving about 153 frost-free days.

In ZIP 53202, plant tomatoes around May 17; this uses the Milwaukee frost station, USDA zone 6a, and tomatoes timing rules.

Your Milwaukee calendar has a 153-day estimated frost-free season. This estimate uses the representative Milwaukee frost station, USDA zone 6a, and tomatoes timing rules.

Source: milwaukee-mitchell frost station, USDA zone 6a, 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 6a Milwaukee frost station University of Wisconsin Extension Updated 2026-06-28

Read the method

Answer first

When to start tomatoes seeds indoors in Milwaukee

In ZIP 53202, start tomatoes seeds indoors around Mar 29, about 42 days before the May 10 last-frost estimate.

Start tomatoes seeds indoors in Milwaukee around Mar 29, about 42 days before the May 10 last-frost estimate.

Seed starting schedule

Tomatoes dates for Milwaukee, WI

Step	Date	How to use it
Start Indoors	March 29, 2026	Start seeds under lights or in a bright indoor seed-starting space.
Transplant Outdoors	May 17, 2026	Move hardened-off seedlings outside after the frost-risk window.

Last frost

When is the last frost in Milwaukee?

Milwaukee (ZIP 53202) has an average last spring frost around May 10.

First frost

When is the first frost in Milwaukee?

The average first fall frost is around Oct 10, giving about 153 frost-free days.

Season map

Tomatoes windows by month

JanFebMarAprMayJunJulAugSepOctNovDec

Start indoors

Mar 29

Transplant

May 17

Harvest

Aug 3

Frost watch

Jul 24

Reminder workflow

Every date has a next action

Start tomatoes indoorsMar 29

Last frost windowMay 10

Transplant tomatoesMay 17

Last tomatoes sowing targetJul 24

First tomatoes harvest windowAug 3

Signal	Value	Why it matters
Last frost estimate	May 10, 2026	Warm-season transplant risk starts falling after this window.
First frost estimate	October 10, 2026	Fall planting counts backward from this date.
Season length	153 days	Longer seasons can support succession crops.
Spacing	18-24 in	Airflow and root space affect yield.
Soil temperature	60 F+	Seeds and transplants stall in cold soil.

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Local data

Why this date changes by ZIP

Milwaukee frost history and USDA zone 6a shift the safe planting window. GrowZone uses a local representative station instead of one national rule.

University of Wisconsin 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 Oct 10. A conservative last sowing target is around Jul 24.