Germantown, WI Frost Dates & Growing Season

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

Last spring frost
May 6
~50% chance of frost after
First fall frost
Oct 8
~50% chance of frost before
Growing season
155 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 22 May 6 May 25
First fall frost Oct 24 Oct 8 Sep 26
Hard freeze (28°F), median last Apr 24 · first Oct 20

Computed from NOAA 1991–2020 climate normals at the GERMANTOWN 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 Germantown

Computed from Germantown'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 11 – Mar 25 May 13 – May 20
🫑 Peppers Feb 25 – Mar 11 May 20 – May 27
🥬 Lettuce Mar 25 – Apr 8 Apr 8 – Apr 22 Apr 8 – May 6
🫛 Peas Mar 25 – Apr 8
🥕 Carrots Apr 15 – May 6
🥦 Broccoli Mar 18 – Apr 1 Apr 15 – Apr 29
🥬 Kale Mar 25 – Apr 8 Apr 8 – Apr 22 Apr 8 – Apr 22
🥒 Cucumbers Apr 8 – Apr 15 May 13 – May 20 May 13 – May 20
🥒 Zucchini Apr 8 – Apr 15 May 13 – May 20 May 13 – May 20
🫘 Green Beans (Bush) May 13 – May 20
🌽 Sweet Corn May 13 – May 20
🌿 Basil Mar 25 – Apr 8 May 13 – May 20 May 20 – May 27
🧄 Garlic Fall: Aug 27 – Sep 24

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 Germantown's dates automatically after a lookup.

Reading the season in Germantown

Roughly 155 frost-free days gives Germantown gardeners room for nearly every common vegetable. Warm-season crops go out after May 6; a fall garden sown in late summer matures comfortably before the Oct 8 frost.

Frequently asked questions

When is the last frost in Germantown, WI?

The average last spring frost in Germantown is around May 6, 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 Germantown, WI?

The average first fall frost in Germantown arrives around Oct 8. 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 Germantown?

About 155 frost-free days on average, from May 6 to Oct 8. That fits nearly all common vegetables, though the longest-season melons and sweet potatoes benefit from transplants.

What USDA zone is Germantown 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.