Highmore 1 W, SD Frost Dates & Growing Season

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

Last spring frost
May 12
~50% chance of frost after
First fall frost
Oct 1
~50% chance of frost before
Growing season
142 days
frost-free stretch
USDA zone
≈ 4b
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost Apr 28 May 12 May 28
First fall frost Oct 14 Oct 1 Sep 17
Hard freeze (28°F), median last May 2 · first Oct 10

Computed from NOAA 1991–2020 climate normals at the HIGHMORE 1 W 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 Highmore 1 W

Computed from Highmore 1 W'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 Mar 17 – Mar 31 May 19 – May 26
🫑 Peppers Mar 3 – Mar 17 May 26 – Jun 2
🥬 Lettuce Mar 31 – Apr 14 Apr 14 – Apr 28 Apr 14 – May 12
🫛 Peas Mar 31 – Apr 14
🥕 Carrots Apr 21 – May 12
🥦 Broccoli Mar 24 – Apr 7 Apr 21 – May 5
🥬 Kale Mar 31 – Apr 14 Apr 14 – Apr 28 Apr 14 – Apr 28
🥒 Cucumbers Apr 14 – Apr 21 May 19 – May 26 May 19 – May 26
🥒 Zucchini Apr 14 – Apr 21 May 19 – May 26 May 19 – May 26
🫘 Green Beans (Bush) May 19 – May 26
🌽 Sweet Corn May 19 – May 26
🌿 Basil Mar 31 – Apr 14 May 19 – May 26 May 26 – Jun 2
🧄 Garlic Fall: Aug 20 – Sep 17

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 Highmore 1 W's dates automatically after a lookup.

Reading the season in Highmore 1 W

At about 142 frost-free days, Highmore 1 W 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 Highmore 1 W, SD?

The average last spring frost in Highmore 1 W is around May 12, 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 Highmore 1 W, SD?

The average first fall frost in Highmore 1 W arrives around Oct 1. 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 Highmore 1 W?

About 142 frost-free days on average, from May 12 to Oct 1. 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 Highmore 1 W 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.