Fall in zone 5bPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 57779 (St. Onge, SD)
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, Spearfish, SD (7 miles away).
- Average last spring frostMay 1250% chance of a 32°F freeze after this date
- Average first fall frostOct 250% chance of a 32°F freeze by this date
- Growing season (frost-free)143 daysmedian, 32°F threshold
- USDA hardiness zone5b-15 to -10°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
46°F Below 50°F
24-hour average · latest 47°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Sundance 8 NNW (34 mi).
4-inch depth
45°F Below 50°F
24-hour average · latest 47°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Sundance 8 NNW (34 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 57779 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 45°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 early May).
Fertilizer window
Lawn region: North (cool-season). 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) | Apr 29 |
| 50% (the "average" last frost) | May 12 |
| 10% (cautious: only 1 year in 10 freezes later) | May 25 |
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 21 |
| 50% (the "average" first frost) | Oct 2 |
| 90% (late: most years have frozen by now) | Oct 17 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | May 22 | Sep 25 |
| 32°F (freeze) | May 12 | Oct 2 |
| 28°F (hard freeze) | Apr 30 | Oct 12 |
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 57779
Dates count from your average last spring frost (May 12) and first fall frost (Oct 2). 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 | Mar 17–31 | May 19–Jun 2 (transplant) | – |
| Pepper (sweet and hot) | Mar 3–17 | May 26–Jun 9 (transplant) | – |
| Eggplant | Mar 3–17 | May 26–Jun 9 (transplant) | – |
| Tomatillo | Mar 17–31 | May 19–Jun 2 (transplant) | – |
| Lettuce | Mar 17–31 | Apr 21–May 12 (transplant) Apr 14–May 26 (sow outdoors) | Aug 7–28 (transplant) Jul 24–Aug 21 (sowing) |
| Spinach | – | Mar 31–Apr 21 (sow outdoors) | Aug 7–28 (sowing) |
| Kale | Mar 17–31 | Apr 14–28 (transplant) Apr 14–28 (sow outdoors) | Jul 10–Aug 7 (transplant) Jun 26–Jul 24 (sowing) |
| Collards | Mar 17–31 | Apr 14–May 12 (transplant) Apr 14–May 12 (sow outdoors) | Jul 10–Aug 7 (transplant) Jun 26–Jul 24 (sowing) |
| Broccoli | Mar 3–17 | Apr 14–28 (transplant) | Jun 26–Jul 24 (transplant) |
| Cabbage | Mar 3–17 | Apr 14–28 (transplant) | Jun 26–Jul 24 (transplant) |
| Cauliflower | Mar 3–17 | Apr 28–May 12 (transplant) | Jun 26–Jul 24 (transplant) |
| Brussels sprouts | Feb 17–Mar 3 | Apr 14–28 (transplant) | Jun 12–Jul 3 (transplant) |
| Kohlrabi | Mar 17–31 | Apr 14–28 (transplant) Apr 14–28 (sow outdoors) | Jul 24–Aug 7 (sowing) |
| Bok choy / Asian greens | – | Apr 14–28 (sow outdoors) | Aug 7–21 (sowing) |
| Arugula | – | Apr 14–May 12 (sow outdoors) | Aug 7–Sep 4 (sowing) |
| Mustard greens | – | Apr 14–May 5 (sow outdoors) | Aug 7–21 (sowing) |
| Swiss chard | Mar 31–Apr 14 | Apr 28–May 19 (transplant) Apr 28–May 26 (sow outdoors) | Jul 24–Aug 7 (sowing) |
| Beet | – | Apr 14–May 12 (sow outdoors) | Jul 24–Aug 7 (sowing) |
| Carrot | – | Apr 21–May 19 (sow outdoors) | Jul 10–24 (sowing) |
| Radish | – | Apr 7–May 19 (sow outdoors) | Aug 21–Sep 4 (sowing) |
| Turnip | – | Apr 14–May 5 (sow outdoors) | Jul 24–Aug 7 (sowing) |
| Parsnip | – | Apr 21–May 12 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 17–Apr 14 (sow outdoors) | Jul 10–24 (sowing) |
| Onion (bulbing) | Feb 17–Mar 3 | Mar 31–Apr 14 (transplant) | – |
| Green onion / scallion | – | Mar 31–Apr 28 (sow outdoors) | Jul 24–Aug 7 (sowing) |
| Leek | Feb 17–Mar 3 | Apr 14–28 (transplant) | – |
| Garlic | – | – | Aug 21–Sep 18 (sowing) |
| Shallot | – | Mar 31–Apr 14 (transplant) | Aug 21–Sep 18 (sowing) |
| Potato | – | Apr 14–28 (transplant) | Jun 12–26 (transplant) |
| Sweet potato | – | Jun 2–16 (transplant) | – |
| Sweet corn | – | May 19–Jun 2 (sow outdoors) | – |
| Bean, bush (snap) | – | May 19–Jun 2 (sow outdoors) | – |
| Bean, pole | – | May 19–Jun 2 (sow outdoors) | – |
| Lima bean | – | May 26–Jun 9 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Jun 2–23 (sow outdoors) | – |
| Cucumber | Apr 14–21 | May 19–Jun 2 (transplant) May 19–Jun 2 (sow outdoors) | – |
| Summer squash / zucchini | Apr 14–21 | May 19–Jun 2 (transplant) May 19–Jun 2 (sow outdoors) | – |
| Winter squash | Apr 14–21 | May 19–Jun 2 (transplant) May 19–Jun 2 (sow outdoors) | – |
| Pumpkin | – | May 19–Jun 2 (sow outdoors) | – |
| Watermelon | Apr 14–21 | May 26–Jun 9 (transplant) May 26–Jun 9 (sow outdoors) | – |
| Cantaloupe / muskmelon | Apr 14–21 | May 26–Jun 9 (transplant) May 26–Jun 9 (sow outdoors) | – |
| Okra | Mar 31–Apr 14 | May 26–Jun 9 (transplant) May 26–Jun 9 (sow outdoors) | – |
| Celery | Feb 17–Mar 3 | May 19–26 (transplant) | – |
| Basil | Mar 31–Apr 14 | May 19–Jun 2 (transplant) May 19–Jun 2 (sow outdoors) | – |
| Cilantro | – | Apr 28–May 26 (sow outdoors) | Aug 7–21 (sowing) |
| Parsley | Mar 3–17 | Apr 28–May 12 (transplant) Apr 21–May 12 (sow outdoors) | – |
| Dill | – | May 12–26 (sow outdoors) | Aug 7–21 (sowing) |
| Sunflower | – | May 12–26 (sow outdoors) | – |
| Asparagus (crowns) | – | Apr 14–28 (transplant) | – |
| Rhubarb (crowns) | – | Apr 14–28 (transplant) | – |
| Strawberry (plants) | – | Apr 14–28 (transplant) | Jul 24–Aug 21 (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.
Where these numbers come from
Station: Spearfish, SD (NOAA GHCN-Daily ID USC00397882), elevation 3,633 ft, 7.3 miles from the ZIP's center point. NOAA completeness flag: S (standard, 24+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Belle Fourche, SD | 8 mi | May 10 | Sep 30 |
| Deadwood, SD | 14 mi | May 24 | Sep 25 |
| Bear Ridge, SD | 14 mi | May 17 | Sep 27 |
The average last-frost dates of these stations span 14 days, a rough guide to local variation. See data sources & methods.
Frost questions for 57779
When is the last frost in 57779?
The average (50% chance) last spring freeze of 32°F for ZIP 57779 is May 12. For a more cautious planting date, use May 25, when only 1 year in 10 still sees a later freeze.
When is the first frost in 57779?
The average first fall freeze is October 2. In 1 year in 10 it comes by September 21.
What hardiness zone is 57779?
ZIP 57779 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 57779 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
57799 Spearfish 57793 Crook City 57783 Spearfish 57762 Nisland 57732 Deadwood 57741 82712 Beulah 57754 Lead
Other ZIP codes in Lawrence County
57732 57754 57759 57783 57793 57799 All Lawrence County frost dates · South Dakota frost dates
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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.