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USDA hardiness zone lookup

Ames, IA — USDA Zone 5a

Ames, Iowa · 159-day growing season

Frost dates and growing season in Ames

USDA hardiness zoneZone 5a
Average last spring frostApril 30
Average first fall frostOctober 6
Growing season length~159 days
Temperature range (F)-20 to -10°F
Temperature range (C)-29 to -23°C

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

These are 50%-probability averages modeled from Ames'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 April 30, 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 Ames

Ames, Iowa sits in USDA Zone 5a, with roughly 159 frost-free days between an average last spring frost around April 30 and a first fall frost around October 6. 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 Ames

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

What to plant in Ames this week

Ames is in high summer — most spring plantings are in. Keep an eye on watering and start planning your fall crop. Cool-season seedlings (broccoli, cabbage, lettuce) can be started indoors for a fall transplant.

Full planting calendar for Ames

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

ZIP codes in Ames

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

Local microclimate notes

Zone tables give you the average — but Amesgardens 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 Ames'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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