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USDA hardiness zone lookup

Naperville (60565) — USDA Zone 6a

Naperville, Illinois · 169-day growing season

Frost dates and growing season for 60565

USDA hardiness zoneZone 6a
Average last spring frostApril 28
Average first fall frostOctober 14
Growing season length~169 days
Temperature range (F)-10 to 0°F
Temperature range (C)-23 to -18°C

These are 50%-probability averages modeled from this ZIP'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 28, but in a colder-than-average year it 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 Naperville

Naperville, Illinois sits in USDA Zone 6a, with roughly 169 frost-free days between an average last spring frost around April 28 and a first fall frost around October 14. 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 Naperville

Naperville falls in USDA Zone 6a, which means the same hardiness constraints apply as the full Zone 6 guide. Vegetables, herbs, and fruit trees rated to Zone 6a (or hardier) will overwinter here in a typical year.

What to plant in Naperville this week

Naperville's last frost is around April 28. 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 Naperville

Crop-by-crop sowing, transplant, and harvest dates calibrated to zone 6 averages:

Local microclimate notes

Zone tables give you the average — but Napervillegardens 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) is more accurate than 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 this ZIP's USDA hardiness zone and regional NOAA 1991-2020 climate normals — they are zone-level estimates, not a per-station record, so treat them as planning guidance and confirm against your own local frost history. Crop recommendations are drawn from US Cooperative Extension references and curated by the Growli editorial team. Last reviewed May 2026.

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