Yale 1 NNW, MI Frost Dates & Growing Season

The two dates every Yale 1 NNW 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 5
~50% chance of frost before
Growing season
146 days
frost-free stretch
USDA zone
≈ 6a
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost Apr 29 May 12 May 26
First fall frost Oct 21 Oct 5 Sep 23
Hard freeze (28°F), median last May 1 · first Oct 20

Computed from NOAA 1991–2020 climate normals at the YALE 1 NNW 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 Yale 1 NNW

Computed from Yale 1 NNW'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 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 24 – Sep 21

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 Yale 1 NNW's dates automatically after a lookup.

Reading the season in Yale 1 NNW

At about 146 frost-free days, Yale 1 NNW 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 Yale 1 NNW, MI?

The average last spring frost in Yale 1 NNW 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 Yale 1 NNW, MI?

The average first fall frost in Yale 1 NNW arrives around Oct 5. 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 Yale 1 NNW?

About 146 frost-free days on average, from May 12 to Oct 5. 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 Yale 1 NNW in?

USDA zone 6a 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.