Twin Lakes Rsvr, CO Frost Dates & Growing Season

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

Last spring frost
Jun 16
~50% chance of frost after
First fall frost
Sep 10
~50% chance of frost before
Growing season
86 days
frost-free stretch
USDA zone
≈ 5b
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost Jun 3 Jun 16 Jun 29
First fall frost Sep 23 Sep 10 Aug 24
Hard freeze (28°F), median last Jun 2 · first Sep 23

Computed from NOAA 1991–2020 climate normals at the TWIN LAKES RSVR 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 Twin Lakes Rsvr

Computed from Twin Lakes Rsvr'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 Apr 21 – May 5 Jun 23 – Jun 30
🫑 Peppers Apr 7 – Apr 21 Jun 30 – Jul 7
🥬 Lettuce May 5 – May 19 May 19 – Jun 2 May 19 – Jun 16
🫛 Peas May 5 – May 19
🥕 Carrots May 26 – Jun 16
🥦 Broccoli Apr 28 – May 12 May 26 – Jun 9
🥬 Kale May 5 – May 19 May 19 – Jun 2 May 19 – Jun 2
🥒 Cucumbers May 19 – May 26 Jun 23 – Jun 30 Jun 23 – Jun 30
🥒 Zucchini May 19 – May 26 Jun 23 – Jun 30 Jun 23 – Jun 30
🫘 Green Beans (Bush) Jun 23 – Jun 30
🌽 Sweet Corn Jun 23 – Jun 30
🌿 Basil May 5 – May 19 Jun 23 – Jun 30 Jun 30 – Jul 7
🧄 Garlic Fall: Jul 30 – Aug 27

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 Twin Lakes Rsvr's dates automatically after a lookup.

Reading the season in Twin Lakes Rsvr

At about 86 frost-free days, Twin Lakes Rsvr 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 Twin Lakes Rsvr, CO?

The average last spring frost in Twin Lakes Rsvr is around Jun 16, 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 Twin Lakes Rsvr, CO?

The average first fall frost in Twin Lakes Rsvr arrives around Sep 10. 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 Twin Lakes Rsvr?

About 86 frost-free days on average, from Jun 16 to Sep 10. 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 Twin Lakes Rsvr 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.