Clinton #1, IA Frost Dates & Growing Season

The two dates every Clinton #1 garden is planned around, plus ready-computed planting windows for the most popular crops.

Last spring frost
Apr 22
~50% chance of frost after
First fall frost
Oct 16
~50% chance of frost before
Growing season
177 days
frost-free stretch
USDA zone
≈ 5b
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost Apr 9 Apr 22 May 8
First fall frost Oct 28 Oct 16 Oct 2
Hard freeze (28°F), median last Apr 13 · first Oct 25

Computed from NOAA 1991–2020 climate normals at the CLINTON #1 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 Clinton #1

Computed from Clinton #1's own frost dates. Click any crop for the full zone-5 growing guide — varieties, spacing, fall plantings, and more.

CropStart seeds indoorsTransplantDirect sow
🍅 Tomatoes Feb 25 – Mar 11 Apr 29 – May 6
🫑 Peppers Feb 11 – Feb 25 May 6 – May 13
🥬 Lettuce Mar 11 – Mar 25 Mar 25 – Apr 8 Mar 25 – Apr 22
🫛 Peas Mar 11 – Mar 25
🥕 Carrots Apr 1 – Apr 22
🥦 Broccoli Mar 4 – Mar 18 Apr 1 – Apr 15
🥬 Kale Mar 11 – Mar 25 Mar 25 – Apr 8 Mar 25 – Apr 8
🥒 Cucumbers Mar 25 – Apr 1 Apr 29 – May 6 Apr 29 – May 6
🥒 Zucchini Mar 25 – Apr 1 Apr 29 – May 6 Apr 29 – May 6
🫘 Green Beans (Bush) Apr 29 – May 6
🌽 Sweet Corn Apr 29 – May 6
🌿 Basil Mar 11 – Mar 25 Apr 29 – May 6 May 6 – May 13
🧄 Garlic Fall: Sep 4 – Oct 2

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 Clinton #1's dates automatically after a lookup.

Reading the season in Clinton #1

Roughly 177 frost-free days gives Clinton #1 gardeners room for nearly every common vegetable. Warm-season crops go out after Apr 22; a fall garden sown in late summer matures comfortably before the Oct 16 frost.

Frequently asked questions

When is the last frost in Clinton #1, IA?

The average last spring frost in Clinton #1 is around Apr 22, 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 Clinton #1, IA?

The average first fall frost in Clinton #1 arrives around Oct 16. 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 Clinton #1?

About 177 frost-free days on average, from Apr 22 to Oct 16. That fits nearly all common vegetables, though the longest-season melons and sweet potatoes benefit from transplants.

What USDA zone is Clinton #1 in?

USDA zone 5b 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.