Clark 3NE, WY Frost Dates & Growing Season

The two dates every Clark 3NE garden is planned around, plus ready-computed planting windows for the most popular crops.

Last spring frost
May 18
~50% chance of frost after
First fall frost
Sep 22
~50% chance of frost before
Growing season
127 days
frost-free stretch
USDA zone
≈ 5a
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost May 6 May 18 Jun 4
First fall frost Oct 4 Sep 22 Sep 8
Hard freeze (28°F), median last May 7 · first Oct 1

Computed from NOAA 1991–2020 climate normals at the CLARK 3NE 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 Clark 3NE

Computed from Clark 3NE'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 Mar 23 – Apr 6 May 25 – Jun 1
🫑 Peppers Mar 9 – Mar 23 Jun 1 – Jun 8
🥬 Lettuce Apr 6 – Apr 20 Apr 20 – May 4 Apr 20 – May 18
🫛 Peas Apr 6 – Apr 20
🥕 Carrots Apr 27 – May 18
🥦 Broccoli Mar 30 – Apr 13 Apr 27 – May 11
🥬 Kale Apr 6 – Apr 20 Apr 20 – May 4 Apr 20 – May 4
🥒 Cucumbers Apr 20 – Apr 27 May 25 – Jun 1 May 25 – Jun 1
🥒 Zucchini Apr 20 – Apr 27 May 25 – Jun 1 May 25 – Jun 1
🫘 Green Beans (Bush) May 25 – Jun 1
🌽 Sweet Corn May 25 – Jun 1
🌿 Basil Apr 6 – Apr 20 May 25 – Jun 1 Jun 1 – Jun 8
🧄 Garlic Fall: Aug 11 – Sep 8

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 Clark 3NE's dates automatically after a lookup.

Reading the season in Clark 3NE

At about 127 frost-free days, Clark 3NE 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 Clark 3NE, WY?

The average last spring frost in Clark 3NE is around May 18, 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 Clark 3NE, WY?

The average first fall frost in Clark 3NE arrives around Sep 22. 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 Clark 3NE?

About 127 frost-free days on average, from May 18 to Sep 22. 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 Clark 3NE in?

USDA zone 5a 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.