Craters Of The Moon, ID Frost Dates & Growing Season

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

Last spring frost
Jun 19
~50% chance of frost after
First fall frost
Sep 9
~50% chance of frost before
Growing season
82 days
frost-free stretch
USDA zone
≈ 4b
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost Jun 5 Jun 19 Jul 2
First fall frost Sep 23 Sep 9 Aug 25
Hard freeze (28°F), median last Jun 7 · first Sep 21

Computed from NOAA 1991–2020 climate normals at the CRATERS OF THE MOON 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 Craters Of The Moon

Computed from Craters Of The Moon's own frost dates. Click any crop for the full zone-4 growing guide — varieties, spacing, fall plantings, and more.

CropStart seeds indoorsTransplantDirect sow
🍅 Tomatoes Apr 24 – May 8 Jun 26 – Jul 3
🫑 Peppers Apr 10 – Apr 24 Jul 3 – Jul 10
🥬 Lettuce May 8 – May 22 May 22 – Jun 5 May 22 – Jun 19
🫛 Peas May 8 – May 22
🥕 Carrots May 29 – Jun 19
🥦 Broccoli May 1 – May 15 May 29 – Jun 12
🥬 Kale May 8 – May 22 May 22 – Jun 5 May 22 – Jun 5
🥒 Cucumbers May 22 – May 29 Jun 26 – Jul 3 Jun 26 – Jul 3
🥒 Zucchini May 22 – May 29 Jun 26 – Jul 3 Jun 26 – Jul 3
🫘 Green Beans (Bush) Jun 26 – Jul 3
🌽 Sweet Corn Jun 26 – Jul 3
🌿 Basil May 8 – May 22 Jun 26 – Jul 3 Jul 3 – Jul 10
🧄 Garlic Fall: Jul 29 – Aug 26

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 Craters Of The Moon's dates automatically after a lookup.

Reading the season in Craters Of The Moon

At about 82 frost-free days, Craters Of The Moon rewards efficiency: start warm-season crops indoors, favor short-season varieties, and lean on cold-tolerant crops — peas, kale, roots — that shrug off the shoulder-season frosts on either end.

Frequently asked questions

When is the last frost in Craters Of The Moon, ID?

The average last spring frost in Craters Of The Moon is around Jun 19, 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 Craters Of The Moon, ID?

The average first fall frost in Craters Of The Moon arrives around Sep 9. 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 Craters Of The Moon?

About 82 frost-free days on average, from Jun 19 to Sep 9. That favors short-season varieties and transplants for warm-season crops, with cool-season vegetables doing the heavy lifting in spring and fall.

What USDA zone is Craters Of The Moon in?

USDA zone 4b 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.