Northdale, CO Frost Dates & Growing Season

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

Last spring frost
Jun 3
~50% chance of frost after
First fall frost
Sep 25
~50% chance of frost before
Growing season
114 days
frost-free stretch
USDA zone
≈ 6b
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost May 19 Jun 3 Jun 19
First fall frost Oct 6 Sep 25 Sep 12
Hard freeze (28°F), median last May 21 · first Oct 4

Computed from NOAA 1991–2020 climate normals at the NORTHDALE 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 Northdale

Computed from Northdale'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 Apr 8 – Apr 22 Jun 10 – Jun 17
🫑 Peppers Mar 25 – Apr 8 Jun 17 – Jun 24
🥬 Lettuce Apr 22 – May 6 May 6 – May 20 May 6 – Jun 3
🫛 Peas Apr 22 – May 6
🥕 Carrots May 13 – Jun 3
🥦 Broccoli Apr 15 – Apr 29 May 13 – May 27
🥬 Kale Apr 22 – May 6 May 6 – May 20 May 6 – May 20
🥒 Cucumbers May 6 – May 13 Jun 10 – Jun 17 Jun 10 – Jun 17
🥒 Zucchini May 6 – May 13 Jun 10 – Jun 17 Jun 10 – Jun 17
🫘 Green Beans (Bush) Jun 10 – Jun 17
🌽 Sweet Corn Jun 10 – Jun 17
🌿 Basil Apr 22 – May 6 Jun 10 – Jun 17 Jun 17 – Jun 24
🧄 Garlic Fall: Aug 14 – Sep 11

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 Northdale's dates automatically after a lookup.

Reading the season in Northdale

At about 114 frost-free days, Northdale 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 Northdale, CO?

The average last spring frost in Northdale is around Jun 3, 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 Northdale, CO?

The average first fall frost in Northdale arrives around Sep 25. 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 Northdale?

About 114 frost-free days on average, from Jun 3 to Sep 25. 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 Northdale in?

USDA zone 6b 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.