Lamoni, IA Frost Dates & Growing Season

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

Last spring frost
Apr 16
~50% chance of frost after
First fall frost
Oct 20
~50% chance of frost before
Growing season
187 days
frost-free stretch
USDA zone
≈ 6b
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost Apr 2 Apr 16 May 2
First fall frost Nov 1 Oct 20 Oct 6
Hard freeze (28°F), median last Apr 5 · first Oct 30

Computed from NOAA 1991–2020 climate normals at the LAMONI 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 Lamoni

Computed from Lamoni'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 19 – Mar 5 Apr 23 – Apr 30
🫑 Peppers Feb 5 – Feb 19 Apr 30 – May 7
🥬 Lettuce Mar 5 – Mar 19 Mar 19 – Apr 2 Mar 19 – Apr 16
🫛 Peas Mar 5 – Mar 19
🥕 Carrots Mar 26 – Apr 16
🥦 Broccoli Feb 26 – Mar 12 Mar 26 – Apr 9
🥬 Kale Mar 5 – Mar 19 Mar 19 – Apr 2 Mar 19 – Apr 2
🥒 Cucumbers Mar 19 – Mar 26 Apr 23 – Apr 30 Apr 23 – Apr 30
🥒 Zucchini Mar 19 – Mar 26 Apr 23 – Apr 30 Apr 23 – Apr 30
🫘 Green Beans (Bush) Apr 23 – Apr 30
🌽 Sweet Corn Apr 23 – Apr 30
🌿 Basil Mar 5 – Mar 19 Apr 23 – Apr 30 Apr 30 – May 7
🧄 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 Lamoni's dates automatically after a lookup.

Reading the season in Lamoni

Roughly 187 frost-free days gives Lamoni gardeners room for nearly every common vegetable. Warm-season crops go out after Apr 16; a fall garden sown in late summer matures comfortably before the Oct 20 frost.

Frequently asked questions

When is the last frost in Lamoni, IA?

The average last spring frost in Lamoni is around Apr 16, 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 Lamoni, IA?

The average first fall frost in Lamoni 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 Lamoni?

About 187 frost-free days on average, from Apr 16 to Oct 20. That fits nearly all common vegetables, though the longest-season melons and sweet potatoes benefit from transplants.

What USDA zone is Lamoni in?

USDA zone 6b 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.