Piper City, IL Frost Dates & Growing Season

The two dates every Piper City garden is planned around, plus ready-computed planting windows for the most popular crops.

Last spring frost
Apr 25
~50% chance of frost after
First fall frost
Oct 20
~50% chance of frost before
Growing season
178 days
frost-free stretch
USDA zone
≈ 6a
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost Apr 11 Apr 25 May 10
First fall frost Oct 31 Oct 20 Oct 2
Hard freeze (28°F), median last Apr 13 · first Oct 31

Computed from NOAA 1991–2020 climate normals at the PIPER CITY station. "Safe" means frost past that date happens only about one year in ten. Your exact garden can still run days either way with elevation and terrain — check your own ZIP with the frost date lookup.

Planting windows for Piper City

Computed from Piper City's own frost dates. Click any crop for the full zone-6 growing guide — varieties, spacing, fall plantings, and more.

CropStart seeds indoorsTransplantDirect sow
🍅 Tomatoes Feb 28 – Mar 14 May 2 – May 9
🫑 Peppers Feb 14 – Feb 28 May 9 – May 16
🥬 Lettuce Mar 14 – Mar 28 Mar 28 – Apr 11 Mar 28 – Apr 25
🫛 Peas Mar 14 – Mar 28
🥕 Carrots Apr 4 – Apr 25
🥦 Broccoli Mar 7 – Mar 21 Apr 4 – Apr 18
🥬 Kale Mar 14 – Mar 28 Mar 28 – Apr 11 Mar 28 – Apr 11
🥒 Cucumbers Mar 28 – Apr 4 May 2 – May 9 May 2 – May 9
🥒 Zucchini Mar 28 – Apr 4 May 2 – May 9 May 2 – May 9
🫘 Green Beans (Bush) May 2 – May 9
🌽 Sweet Corn May 2 – May 9
🌿 Basil Mar 14 – Mar 28 May 2 – May 9 May 9 – May 16
🧄 Garlic Fall: Sep 8 – Oct 6

Want this for all 50 crops, or as a printable seed-shelf schedule? Use the planting calendar and the seed starting scheduler — both can use Piper City's dates automatically after a lookup.

Reading the season in Piper City

Roughly 178 frost-free days gives Piper City gardeners room for nearly every common vegetable. Warm-season crops go out after Apr 25; a fall garden sown in late summer matures comfortably before the Oct 20 frost.

Frequently asked questions

When is the last frost in Piper City, IL?

The average last spring frost in Piper City is around Apr 25, based on 1991–2020 climate normals. That's a median — about half of years see a later frost, so tender crops are safest going out a week or two after this date.

When is the first frost in Piper City, IL?

The average first fall frost in Piper City arrives around Oct 20. Crops still in the garden need to mature before then, and frost-tender plants need harvesting or protection as the date approaches.

How long is the growing season in Piper City?

About 178 frost-free days on average, from Apr 25 to Oct 20. That fits nearly all common vegetables, though the longest-season melons and sweet potatoes benefit from transplants.

What USDA zone is Piper City in?

USDA zone 6a on the 2023 Plant Hardiness Zone Map. Note that zones describe winter cold, not frost timing — these frost dates are the numbers to plan plantings around.