Fall in zone 5bPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 80512 (Larimer County, CO)
Average last spring and first fall frost dates with 10%, 50% and 90% odds, from NOAA's 1991–2020 climate normals for the nearest weather station, Rustic 9WSW, CO (9 miles away).
- Average last spring frostJun 550% chance of a 32°F freeze after this date
- Average first fall frostSep 1650% chance of a 32°F freeze by this date
- Growing season (frost-free)101 daysmedian, 32°F threshold
- USDA hardiness zone5b-15 to -10°F avg. coldest night
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Frost and freeze alerts from the NWS forecast for 80512, the spring soil-temperature heads-up for pre-emergent, and a short weekly yard-timing email.
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This week in your yard
As of Oct 18, 2026, from your frost dates, zone and soil temperature. Lawn timing · Vegetables · Pruning · Plants
Soil temperature now
2-inch depth
46°F Below 50°F
24-hour average · latest 46°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Boulder 14 W (41 mi), Nunn 7 NNE (44 mi), Nunn #1 (46 mi).
4-inch depth
48°F Below 50°F
24-hour average · latest 49°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Boulder 14 W (41 mi), Nunn 7 NNE (44 mi), Nunn #1 (46 mi).
Fall: Texas A&M AgriLife times fall pre-emergent (for winter weeds such as annual bluegrass) to soil cooling to about 70°F for several days. The 50–55°F band is the spring trigger. Always read and follow the product label.
7-day forecast and frost risk
The latest National Weather Service 7-day forecast and any Frost Advisory or Freeze Warning for 80512 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 48°F at 4 inches (estimated soil temperature, not a station reading). Fall pre-emergent window is mostly past. Next: spring, when soil reaches 50°F (typically mid-April to mid-May).
Fertilizer window
Lawn region: Mountain West and High Plains. Timing only; always follow the product label.
- Kentucky bluegrass (cool-season): Early fall: Around Labor Day (late August–September); Late fall: Late October–November, before the ground freezes; Late spring: Optional around Memorial Day. Avoid: Early-spring and midsummer feeding (pushes top growth, favors crabgrass).
Plant now
No vegetable planting windows are open this week.
Prune now
No frost-timed pruning windows are open this week.
Spring-flowering shrubs are pruned right after their flowers fade, not by date. See the pruning guide.
Last spring frost odds
| Chance of a 32°F freeze after this date | Date |
|---|---|
| 90% (early: most years still freeze after this) | May 24 |
| 50% (the "average" last frost) | Jun 5 |
| 10% (cautious: only 1 year in 10 freezes later) | Jun 20 |
Most gardeners plant frost-tender crops (tomatoes, peppers, basil) after the 50% date, and closer to the 10% date for less risk.
First fall frost odds
| Chance the first 32°F freeze has happened by this date | Date |
|---|---|
| 10% (early: 1 year in 10 freezes this soon) | Sep 5 |
| 50% (the "average" first frost) | Sep 16 |
| 90% (late: most years have frozen by now) | Sep 29 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | n/a | n/a |
| 32°F (freeze) | Jun 5 | Sep 16 |
| 28°F (hard freeze) | May 22 | Sep 26 |
n/a means NOAA did not publish a date at that threshold for this station (usually because it rarely gets that cold).
Vegetable planting calendar for 80512
Dates count from your average last spring frost (Jun 5) and first fall frost (Sep 16). Half of years have a frost after the spring date, so give tender crops (tomatoes, peppers, squash) some slack.
| Crop | Start indoors | Spring planting | Fall planting |
|---|---|---|---|
| Tomato | Apr 10–24 | Jun 12–26 (transplant) | – |
| Pepper (sweet and hot) | Mar 27–Apr 10 | Jun 19–Jul 3 (transplant) | – |
| Eggplant | Mar 27–Apr 10 | Jun 19–Jul 3 (transplant) | – |
| Tomatillo | Apr 10–24 | Jun 12–26 (transplant) | – |
| Lettuce | Apr 10–24 | May 15–Jun 5 (transplant) May 8–Jun 19 (sow outdoors) | Jul 22–Aug 12 (transplant) Jul 8–Aug 5 (sowing) |
| Spinach | – | Apr 24–May 15 (sow outdoors) | Jul 22–Aug 12 (sowing) |
| Kale | Apr 10–24 | May 8–22 (transplant) May 8–22 (sow outdoors) | Jun 24–Jul 22 (transplant) Jun 10–Jul 8 (sowing) |
| Collards | Apr 10–24 | May 8–Jun 5 (transplant) May 8–Jun 5 (sow outdoors) | Jun 24–Jul 22 (transplant) Jun 10–Jul 8 (sowing) |
| Broccoli | Mar 27–Apr 10 | May 8–22 (transplant) | Jun 10–Jul 8 (transplant) |
| Cabbage | Mar 27–Apr 10 | May 8–22 (transplant) | Jun 10–Jul 8 (transplant) |
| Cauliflower | Mar 27–Apr 10 | May 22–Jun 5 (transplant) | Jun 10–Jul 8 (transplant) |
| Brussels sprouts | Mar 13–27 | May 8–22 (transplant) | May 27–Jun 17 (transplant) |
| Kohlrabi | Apr 10–24 | May 8–22 (transplant) May 8–22 (sow outdoors) | Jul 8–22 (sowing) |
| Bok choy / Asian greens | – | May 8–22 (sow outdoors) | Jul 22–Aug 5 (sowing) |
| Arugula | – | May 8–Jun 5 (sow outdoors) | Jul 22–Aug 19 (sowing) |
| Mustard greens | – | May 8–29 (sow outdoors) | Jul 22–Aug 5 (sowing) |
| Swiss chard | Apr 24–May 8 | May 22–Jun 12 (transplant) May 22–Jun 19 (sow outdoors) | Jul 8–22 (sowing) |
| Beet | – | May 8–Jun 5 (sow outdoors) | Jul 8–22 (sowing) |
| Carrot | – | May 15–Jun 12 (sow outdoors) | Jun 24–Jul 8 (sowing) |
| Radish | – | May 1–Jun 12 (sow outdoors) | Aug 5–19 (sowing) |
| Turnip | – | May 8–29 (sow outdoors) | Jul 8–22 (sowing) |
| Parsnip | – | May 15–Jun 5 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Apr 10–May 8 (sow outdoors) | Jun 24–Jul 8 (sowing) |
| Onion (bulbing) | Mar 13–27 | Apr 24–May 8 (transplant) | – |
| Green onion / scallion | – | Apr 24–May 22 (sow outdoors) | Jul 8–22 (sowing) |
| Leek | Mar 13–27 | May 8–22 (transplant) | – |
| Garlic | – | – | Aug 5–Sep 2 (sowing) |
| Shallot | – | Apr 24–May 8 (transplant) | Aug 5–Sep 2 (sowing) |
| Potato | – | May 8–22 (transplant) | May 27–Jun 10 (transplant) |
| Sweet potato | – | Jun 26–Jul 10 (transplant) | – |
| Sweet corn | – | Jun 12–26 (sow outdoors) | – |
| Bean, bush (snap) | – | Jun 12–26 (sow outdoors) | – |
| Bean, pole | – | Jun 12–26 (sow outdoors) | – |
| Lima bean | – | Jun 19–Jul 3 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Jun 26–Jul 17 (sow outdoors) | – |
| Cucumber | May 8–15 | Jun 12–26 (transplant) Jun 12–26 (sow outdoors) | – |
| Summer squash / zucchini | May 8–15 | Jun 12–26 (transplant) Jun 12–26 (sow outdoors) | – |
| Winter squash | May 8–15 | Jun 12–26 (transplant) Jun 12–26 (sow outdoors) | – |
| Pumpkin | – | Jun 12–26 (sow outdoors) | – |
| Watermelon | May 8–15 | Jun 19–Jul 3 (transplant) Jun 19–Jul 3 (sow outdoors) | – |
| Cantaloupe / muskmelon | May 8–15 | Jun 19–Jul 3 (transplant) Jun 19–Jul 3 (sow outdoors) | – |
| Okra | Apr 24–May 8 | Jun 19–Jul 3 (transplant) Jun 19–Jul 3 (sow outdoors) | – |
| Celery | Mar 13–27 | Jun 12–19 (transplant) | – |
| Basil | Apr 24–May 8 | Jun 12–26 (transplant) Jun 12–26 (sow outdoors) | – |
| Cilantro | – | May 22–Jun 19 (sow outdoors) | Jul 22–Aug 5 (sowing) |
| Parsley | Mar 27–Apr 10 | May 22–Jun 5 (transplant) May 15–Jun 5 (sow outdoors) | – |
| Dill | – | Jun 5–19 (sow outdoors) | Jul 22–Aug 5 (sowing) |
| Sunflower | – | Jun 5–19 (sow outdoors) | – |
| Asparagus (crowns) | – | May 8–22 (transplant) | – |
| Rhubarb (crowns) | – | May 8–22 (transplant) | – |
| Strawberry (plants) | – | May 8–22 (transplant) | Jul 8–Aug 5 (transplant) |
Typical ranges from university extension planting calendars, adjusted to your frost dates. Probabilities, not guarantees. Fall windows that would overlap spring planting are left out, as are fall crops of frost-tender plants where the frost-free season is under 210 days.
Plants that do well here
Colorado has a university or garden plant program: Plant Select®. Plant frost-tender annuals after June 5 here (the average last frost). Not affiliated with the program.
Where these numbers come from
Station: Rustic 9WSW, CO (NOAA GHCN-Daily ID USC00057296), elevation 7,700 ft, 8.7 miles from the ZIP's center point. NOAA completeness flag: S (standard, 24+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Buckhorn Mtn 1 E, CO | 15 mi | May 21 | Sep 29 |
| Estes Park 3 SSE, CO | 20 mi | May 30 | Sep 17 |
| Waterdale, CO | 24 mi | May 12 | Oct 1 |
The average last-frost dates of these stations span 24 days, a rough guide to local variation. See data sources & methods.
Frost questions for 80512
When is the last frost in 80512?
The average (50% chance) last spring freeze of 32°F for ZIP 80512 is June 5. For a more cautious planting date, use June 20, when only 1 year in 10 still sees a later freeze.
When is the first frost in 80512?
The average first fall freeze is September 16. In 1 year in 10 it comes by September 5.
What hardiness zone is 80512?
ZIP 80512 is in USDA zone 5b (-15 to -10°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 80512 right now?
This page shows the latest 2-inch and 4-inch soil temperature from the nearest public soil station (USDA SCAN, NOAA USCRN or TexMesonet), or a labeled estimate when no station is close, against the 50–55°F spring pre-emergent band.
Nearby ZIP codes
80532 80515 80545 Red Feather Lakes 80517 Estes Park 80538 Loveland 80536 80535 Laporte 82063
Other ZIP codes in Larimer County
80513 80515 80517 80521 80524 80525 80526 80528 80532 80535 80536 80537 80538 80545 80547 80549 82063 All Larimer County frost dates · Colorado frost dates
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Weekly yard timing, plus frost and soil-temperature alerts for your ZIP code.
- Freeze alerts
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- Weekly yard to-dos
Free. One weekly email plus alerts when your ZIP has a frost or a soil-temperature change worth acting on. After you submit, Kit (our email provider) sends a confirmation email: check your email and click the link to confirm. You aren't subscribed until you do. We collect only your email address and ZIP, sent to Kit to deliver The Dial. Unsubscribe anytime.