Fall in zone 5aPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 80456 (Park 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, Grant, CO (10 miles away).
- Average last spring frostJun 1550% chance of a 32°F freeze after this date
- Average first fall frostSep 950% chance of a 32°F freeze by this date
- Growing season (frost-free)84 daysmedian, 32°F threshold
- USDA hardiness zone5a-20 to -15°F avg. coldest night
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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
42°F Below 50°F
24-hour average · latest 41°F, as of Oct 18, 1:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Boulder 14 W (51 mi).
4-inch depth
42°F Below 50°F
24-hour average · latest 42°F, as of Oct 18, 1:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Boulder 14 W (51 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 80456 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 42°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) | Jun 1 |
| 50% (the "average" last frost) | Jun 15 |
| 10% (cautious: only 1 year in 10 freezes later) | Jun 30 |
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) | Aug 26 |
| 50% (the "average" first frost) | Sep 9 |
| 90% (late: most years have frozen by now) | Sep 22 |
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 15 | Sep 9 |
| 28°F (hard freeze) | May 30 | Sep 22 |
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 80456
Dates count from your average last spring frost (Jun 15) and first fall frost (Sep 9). 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 20–May 4 | Jun 22–Jul 6 (transplant) | – |
| Pepper (sweet and hot) | Apr 6–20 | Jun 29–Jul 13 (transplant) | – |
| Eggplant | Apr 6–20 | Jun 29–Jul 13 (transplant) | – |
| Tomatillo | Apr 20–May 4 | Jun 22–Jul 6 (transplant) | – |
| Lettuce | Apr 20–May 4 | May 25–Jun 15 (transplant) May 18–Jun 29 (sow outdoors) | Jul 15–Aug 5 (transplant) Jul 1–29 (sowing) |
| Spinach | – | May 4–25 (sow outdoors) | Jul 15–Aug 5 (sowing) |
| Kale | Apr 20–May 4 | May 18–Jun 1 (transplant) May 18–Jun 1 (sow outdoors) | Jun 17–Jul 15 (transplant) Jun 3–Jul 1 (sowing) |
| Collards | Apr 20–May 4 | May 18–Jun 15 (transplant) May 18–Jun 15 (sow outdoors) | Jun 17–Jul 15 (transplant) |
| Broccoli | Apr 6–20 | May 18–Jun 1 (transplant) | Jun 3–Jul 1 (transplant) |
| Cabbage | Apr 6–20 | May 18–Jun 1 (transplant) | Jun 3–Jul 1 (transplant) |
| Cauliflower | Apr 6–20 | Jun 1–15 (transplant) | – |
| Brussels sprouts | Mar 23–Apr 6 | May 18–Jun 1 (transplant) | – |
| Kohlrabi | Apr 20–May 4 | May 18–Jun 1 (transplant) May 18–Jun 1 (sow outdoors) | Jul 1–15 (sowing) |
| Bok choy / Asian greens | – | May 18–Jun 1 (sow outdoors) | Jul 15–29 (sowing) |
| Arugula | – | May 18–Jun 15 (sow outdoors) | Jul 15–Aug 12 (sowing) |
| Mustard greens | – | May 18–Jun 8 (sow outdoors) | Jul 15–29 (sowing) |
| Swiss chard | May 4–18 | Jun 1–22 (transplant) Jun 1–29 (sow outdoors) | Jul 1–15 (sowing) |
| Beet | – | May 18–Jun 15 (sow outdoors) | Jul 1–15 (sowing) |
| Carrot | – | May 25–Jun 22 (sow outdoors) | – |
| Radish | – | May 11–Jun 22 (sow outdoors) | Jul 29–Aug 12 (sowing) |
| Turnip | – | May 18–Jun 8 (sow outdoors) | Jul 1–15 (sowing) |
| Parsnip | – | May 25–Jun 15 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Apr 20–May 18 (sow outdoors) | Jun 17–Jul 1 (sowing) |
| Onion (bulbing) | Mar 23–Apr 6 | May 4–18 (transplant) | – |
| Green onion / scallion | – | May 4–Jun 1 (sow outdoors) | Jul 1–15 (sowing) |
| Leek | Mar 23–Apr 6 | May 18–Jun 1 (transplant) | – |
| Garlic | – | – | Jul 29–Aug 26 (sowing) |
| Shallot | – | May 4–18 (transplant) | Jul 29–Aug 26 (sowing) |
| Potato | – | May 18–Jun 1 (transplant) | – |
| Sweet potato | – | Jul 6–20 (transplant) | – |
| Sweet corn | – | Jun 22–Jul 6 (sow outdoors) | – |
| Bean, bush (snap) | – | Jun 22–Jul 6 (sow outdoors) | – |
| Bean, pole | – | Jun 22–Jul 6 (sow outdoors) | – |
| Lima bean | – | Jun 29–Jul 13 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Jul 6–27 (sow outdoors) | – |
| Cucumber | May 18–25 | Jun 22–Jul 6 (transplant) Jun 22–Jul 6 (sow outdoors) | – |
| Summer squash / zucchini | May 18–25 | Jun 22–Jul 6 (transplant) Jun 22–Jul 6 (sow outdoors) | – |
| Winter squash | May 18–25 | Jun 22–Jul 6 (transplant) Jun 22–Jul 6 (sow outdoors) | – |
| Pumpkin | – | Jun 22–Jul 6 (sow outdoors) | – |
| Watermelon | May 18–25 | Jun 29–Jul 13 (transplant) Jun 29–Jul 13 (sow outdoors) | – |
| Cantaloupe / muskmelon | May 18–25 | Jun 29–Jul 13 (transplant) Jun 29–Jul 13 (sow outdoors) | – |
| Okra | May 4–18 | Jun 29–Jul 13 (transplant) Jun 29–Jul 13 (sow outdoors) | – |
| Celery | Mar 23–Apr 6 | Jun 22–29 (transplant) | – |
| Basil | May 4–18 | Jun 22–Jul 6 (transplant) Jun 22–Jul 6 (sow outdoors) | – |
| Cilantro | – | Jun 1–29 (sow outdoors) | Jul 15–29 (sowing) |
| Parsley | Apr 6–20 | Jun 1–15 (transplant) May 25–Jun 15 (sow outdoors) | – |
| Dill | – | Jun 15–29 (sow outdoors) | Jul 15–29 (sowing) |
| Sunflower | – | Jun 15–29 (sow outdoors) | – |
| Asparagus (crowns) | – | May 18–Jun 1 (transplant) | – |
| Rhubarb (crowns) | – | May 18–Jun 1 (transplant) | – |
| Strawberry (plants) | – | May 18–Jun 1 (transplant) | Jul 1–29 (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 15 here (the average last frost). Not affiliated with the program.
Where these numbers come from
Station: Grant, CO (NOAA GHCN-Daily ID USC00053530), elevation 8,675 ft, 10.4 miles from the ZIP's center point. NOAA completeness flag: S (standard, 24+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Bailey, CO | 13 mi | Jun 16 | Sep 8 |
| Fairplay S Park Rd, CO | 17 mi | Jun 16 | Sep 9 |
| Cheesman, CO | 23 mi | May 17 | Oct 1 |
The average last-frost dates of these stations span 30 days, a rough guide to local variation. See data sources & methods.
Frost questions for 80456
When is the last frost in 80456?
The average (50% chance) last spring freeze of 32°F for ZIP 80456 is June 15. For a more cautious planting date, use June 30, when only 1 year in 10 still sees a later freeze.
When is the first frost in 80456?
The average first fall freeze is September 9. In 1 year in 10 it comes by August 26.
What hardiness zone is 80456?
ZIP 80456 is in USDA zone 5a (-20 to -15°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 80456 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
80475 80432 80448 80421 80470 80424 Breckenridge 80827 80444 Georgetown
Other ZIP codes in Park County
80420 80421 80432 80440 80448 80449 80475 80820 80827 All Park County frost dates · Colorado frost dates
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Weekly yard timing, plus frost and soil-temperature alerts for your ZIP code.
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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.