Fall in zone 5aPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 81433 (Silverton, 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, Rio Grande Rsvr, CO (17 miles away).
- Average last spring frostJun 1550% chance of a 32°F freeze after this date
- Average first fall frostSep 1150% chance of a 32°F freeze by this date
- Growing season (frost-free)85 daysmedian, 32°F threshold
- USDA hardiness zone5a-20 to -15°F avg. coldest night
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Frost and freeze alerts from the NWS forecast for 81433, 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
47°F Below 50°F
24-hour average · latest 46°F, as of Oct 18, 1:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Montrose 11 ENE (57 mi), Cortez 8 SE (60 mi).
4-inch depth
48°F Below 50°F
24-hour average · latest 48°F, as of Oct 18, 1:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Montrose 11 ENE (57 mi), Cortez 8 SE (60 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 81433 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) | Jun 2 |
| 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 27 |
| 50% (the "average" first frost) | Sep 11 |
| 90% (late: most years have frozen by now) | Sep 23 |
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 11 |
| 28°F (hard freeze) | May 31 | Sep 23 |
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 81433
Dates count from your average last spring frost (Jun 15) and first fall frost (Sep 11). 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 17–Aug 7 (transplant) Jul 3–31 (sowing) |
| Spinach | – | May 4–25 (sow outdoors) | Jul 17–Aug 7 (sowing) |
| Kale | Apr 20–May 4 | May 18–Jun 1 (transplant) May 18–Jun 1 (sow outdoors) | Jun 19–Jul 17 (transplant) Jun 5–Jul 3 (sowing) |
| Collards | Apr 20–May 4 | May 18–Jun 15 (transplant) May 18–Jun 15 (sow outdoors) | Jun 19–Jul 17 (transplant) |
| Broccoli | Apr 6–20 | May 18–Jun 1 (transplant) | Jun 5–Jul 3 (transplant) |
| Cabbage | Apr 6–20 | May 18–Jun 1 (transplant) | Jun 5–Jul 3 (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 3–17 (sowing) |
| Bok choy / Asian greens | – | May 18–Jun 1 (sow outdoors) | Jul 17–31 (sowing) |
| Arugula | – | May 18–Jun 15 (sow outdoors) | Jul 17–Aug 14 (sowing) |
| Mustard greens | – | May 18–Jun 8 (sow outdoors) | Jul 17–31 (sowing) |
| Swiss chard | May 4–18 | Jun 1–22 (transplant) Jun 1–29 (sow outdoors) | Jul 3–17 (sowing) |
| Beet | – | May 18–Jun 15 (sow outdoors) | Jul 3–17 (sowing) |
| Carrot | – | May 25–Jun 22 (sow outdoors) | – |
| Radish | – | May 11–Jun 22 (sow outdoors) | Jul 31–Aug 14 (sowing) |
| Turnip | – | May 18–Jun 8 (sow outdoors) | Jul 3–17 (sowing) |
| Parsnip | – | May 25–Jun 15 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Apr 20–May 18 (sow outdoors) | Jun 19–Jul 3 (sowing) |
| Onion (bulbing) | Mar 23–Apr 6 | May 4–18 (transplant) | – |
| Green onion / scallion | – | May 4–Jun 1 (sow outdoors) | Jul 3–17 (sowing) |
| Leek | Mar 23–Apr 6 | May 18–Jun 1 (transplant) | – |
| Garlic | – | – | Jul 31–Aug 28 (sowing) |
| Shallot | – | May 4–18 (transplant) | Jul 31–Aug 28 (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 17–31 (sowing) |
| Parsley | Apr 6–20 | Jun 1–15 (transplant) May 25–Jun 15 (sow outdoors) | – |
| Dill | – | Jun 15–29 (sow outdoors) | Jul 17–31 (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 3–31 (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: Rio Grande Rsvr, CO (NOAA GHCN-Daily ID USC00057050), elevation 9,492 ft, 17.1 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Ouray, CO | 21 mi | May 17 | Oct 1 |
| Ouray #2, CO | 22 mi | May 18 | Oct 4 |
| Vallecito Reservoir, CO | 23 mi | May 18 | Oct 11 |
The average last-frost dates of these stations span 29 days, a rough guide to local variation. See data sources & methods.
Frost questions for 81433
When is the last frost in 81433?
The average (50% chance) last spring freeze of 32°F for ZIP 81433 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 81433?
The average first fall freeze is September 11. In 1 year in 10 it comes by August 27.
What hardiness zone is 81433?
ZIP 81433 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 81433 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
81426 Ophir 81301 Durango 81235 Cathedral 81427 Ouray 81435 Mountain Village 81332 Rico 81130 City of Creede 81122 Bayfield
Other ZIP codes in San Juan County
None. All San Juan 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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