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USDA hardiness zone lookup

Waukesha, WI — USDA Zone 5b

Waukesha, Wisconsin · 158-day growing season

Frost dates and growing season in Waukesha

USDA hardiness zoneZone 5b
Average last spring frostMay 4
Average first fall frostOctober 9
Growing season length~158 days
Temperature range (F)-20 to -10°F
Temperature range (C)-29 to -23°C

All of Waukesha's mapped ZIP codes fall in the same hardiness band, Zone 5b.

These are 50%-probability averages modeled from Waukesha's USDA hardiness zone and regional climate normals — not a single-station reading. In a typical year the last spring frost will have passed by May 4, but a colder-than-average year can run 1-2 weeks later. Plant tender crops (tomatoes, peppers, basil) once both soil and night temperatures are consistently warm — a thermometer beats the calendar.

Growing season in Waukesha

Waukesha, Wisconsin sits in USDA Zone 5b, with roughly 158 frost-free days between an average last spring frost around May 4 and a first fall frost around October 9. That is a standard temperate season — most common vegetables finish comfortably, and a single main planting plus one succession round works well.

What grows in Waukesha

Waukesha falls in USDA Zone 5b, so the same hardiness constraints apply as the full Zone 5 guide. Vegetables, herbs, and fruit trees rated to Zone 5b (or hardier) will overwinter here in a typical year.

What to plant in Waukesha this week

Waukesha's last frost is around May 4. This is the spring transplant window — start tomatoes and peppers indoors if you haven't, and direct-sow cold-tolerant crops now.

Full planting calendar for Waukesha

Crop-by-crop sowing, transplant, and harvest dates calibrated to zone 5 averages:

ZIP codes in Waukesha

Drill down to the precise frost window and planting calendar for a specific ZIP in Waukesha:

Local microclimate notes

Zone tables give you the average — but Waukeshagardens vary. South-facing walls and paved areas can run a full half-zone warmer than the published rating. Low-lying spots, frost pockets, and shaded north sides can run colder. If you've gardened here a few seasons, your own frost record — the last time you actually got frost damage — beats any national average.

Source and methodology

Hardiness zone from the USDA Plant Hardiness Zone Map (2023 revision). Frost-date and growing-season figures are modeled from Waukesha's USDA hardiness zone and regional NOAA 1991-2020 climate normals — zone-level estimates, not a per-station record, so treat them as planning guidance and confirm against your own local frost history. Crop recommendations draw on US Cooperative Extension references, curated by the Growli editorial team. Last reviewed June 2026.

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