Paradox 2N, CO Frost Dates & Growing Season

The two dates every Paradox 2N garden is planned around, plus ready-computed planting windows for the most popular crops.

Last spring frost
May 11
~50% chance of frost after
First fall frost
Oct 5
~50% chance of frost before
Growing season
147 days
frost-free stretch
USDA zone
≈ 5b
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost Apr 29 May 11 May 29
First fall frost Oct 18 Oct 5 Sep 23
Hard freeze (28°F), median last Apr 30 · first Oct 15

Computed from NOAA 1991–2020 climate normals at the PARADOX 2N 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 Paradox 2N

Computed from Paradox 2N'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 16 – Mar 30 May 18 – May 25
🫑 Peppers Mar 2 – Mar 16 May 25 – Jun 1
🥬 Lettuce Mar 30 – Apr 13 Apr 13 – Apr 27 Apr 13 – May 11
🫛 Peas Mar 30 – Apr 13
🥕 Carrots Apr 20 – May 11
🥦 Broccoli Mar 23 – Apr 6 Apr 20 – May 4
🥬 Kale Mar 30 – Apr 13 Apr 13 – Apr 27 Apr 13 – Apr 27
🥒 Cucumbers Apr 13 – Apr 20 May 18 – May 25 May 18 – May 25
🥒 Zucchini Apr 13 – Apr 20 May 18 – May 25 May 18 – May 25
🫘 Green Beans (Bush) May 18 – May 25
🌽 Sweet Corn May 18 – May 25
🌿 Basil Mar 30 – Apr 13 May 18 – May 25 May 25 – Jun 1
🧄 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 Paradox 2N's dates automatically after a lookup.

Reading the season in Paradox 2N

At about 147 frost-free days, Paradox 2N 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 Paradox 2N, CO?

The average last spring frost in Paradox 2N is around May 11, 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 Paradox 2N, CO?

The average first fall frost in Paradox 2N 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 Paradox 2N?

About 147 frost-free days on average, from May 11 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 Paradox 2N in?

USDA zone 5b 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.