Frost dates for ZIP 57650 (Harding County, 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, Ralph 1 N, SD (4 miles away).
- Average last spring frostMay 1850% chance of a 32°F freeze after this date
- Average first fall frostSep 2350% chance of a 32°F freeze by this date
- Growing season (frost-free)126 daysmedian, 32°F threshold
- USDA hardiness zone4b-25 to -20°F avg. coldest night
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This week in your yard
As of Oct 17, 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 52°F, as of Oct 17, 9:00 PM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Buffalo 13 ESE (25 mi).
4-inch depth
48°F Below 50°F
24-hour average · latest 52°F, as of Oct 17, 9:00 PM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Buffalo 13 ESE (25 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 57650 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 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) | May 7 |
| 50% (the "average" last frost) | May 18 |
| 10% (cautious: only 1 year in 10 freezes later) | May 31 |
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 8 |
| 50% (the "average" first frost) | Sep 23 |
| 90% (late: most years have frozen by now) | Oct 6 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | May 28 | Sep 14 |
| 32°F (freeze) | May 18 | Sep 23 |
| 28°F (hard freeze) | May 8 | Oct 1 |
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 57650
Dates count from your average last spring frost (May 18) and first fall frost (Sep 23). 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 23–Apr 6 | May 25–Jun 8 (transplant) | – |
| Pepper (sweet and hot) | Mar 9–23 | Jun 1–15 (transplant) | – |
| Eggplant | Mar 9–23 | Jun 1–15 (transplant) | – |
| Tomatillo | Mar 23–Apr 6 | May 25–Jun 8 (transplant) | – |
| Lettuce | Mar 23–Apr 6 | Apr 27–May 18 (transplant) Apr 20–Jun 1 (sow outdoors) | Jul 29–Aug 19 (transplant) Jul 15–Aug 12 (sowing) |
| Spinach | – | Apr 6–27 (sow outdoors) | Jul 29–Aug 19 (sowing) |
| Kale | Mar 23–Apr 6 | Apr 20–May 4 (transplant) Apr 20–May 4 (sow outdoors) | Jul 1–29 (transplant) Jun 17–Jul 15 (sowing) |
| Collards | Mar 23–Apr 6 | Apr 20–May 18 (transplant) Apr 20–May 18 (sow outdoors) | Jul 1–29 (transplant) Jun 17–Jul 15 (sowing) |
| Broccoli | Mar 9–23 | Apr 20–May 4 (transplant) | Jun 17–Jul 15 (transplant) |
| Cabbage | Mar 9–23 | Apr 20–May 4 (transplant) | Jun 17–Jul 15 (transplant) |
| Cauliflower | Mar 9–23 | May 4–18 (transplant) | Jun 17–Jul 15 (transplant) |
| Brussels sprouts | Feb 23–Mar 9 | Apr 20–May 4 (transplant) | Jun 3–24 (transplant) |
| Kohlrabi | Mar 23–Apr 6 | Apr 20–May 4 (transplant) Apr 20–May 4 (sow outdoors) | Jul 15–29 (sowing) |
| Bok choy / Asian greens | – | Apr 20–May 4 (sow outdoors) | Jul 29–Aug 12 (sowing) |
| Arugula | – | Apr 20–May 18 (sow outdoors) | Jul 29–Aug 26 (sowing) |
| Mustard greens | – | Apr 20–May 11 (sow outdoors) | Jul 29–Aug 12 (sowing) |
| Swiss chard | Apr 6–20 | May 4–25 (transplant) May 4–Jun 1 (sow outdoors) | Jul 15–29 (sowing) |
| Beet | – | Apr 20–May 18 (sow outdoors) | Jul 15–29 (sowing) |
| Carrot | – | Apr 27–May 25 (sow outdoors) | Jul 1–15 (sowing) |
| Radish | – | Apr 13–May 25 (sow outdoors) | Aug 12–26 (sowing) |
| Turnip | – | Apr 20–May 11 (sow outdoors) | Jul 15–29 (sowing) |
| Parsnip | – | Apr 27–May 18 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 23–Apr 20 (sow outdoors) | Jul 1–15 (sowing) |
| Onion (bulbing) | Feb 23–Mar 9 | Apr 6–20 (transplant) | – |
| Green onion / scallion | – | Apr 6–May 4 (sow outdoors) | Jul 15–29 (sowing) |
| Leek | Feb 23–Mar 9 | Apr 20–May 4 (transplant) | – |
| Garlic | – | – | Aug 12–Sep 9 (sowing) |
| Shallot | – | Apr 6–20 (transplant) | Aug 12–Sep 9 (sowing) |
| Potato | – | Apr 20–May 4 (transplant) | Jun 3–17 (transplant) |
| Sweet potato | – | Jun 8–22 (transplant) | – |
| Sweet corn | – | May 25–Jun 8 (sow outdoors) | – |
| Bean, bush (snap) | – | May 25–Jun 8 (sow outdoors) | – |
| Bean, pole | – | May 25–Jun 8 (sow outdoors) | – |
| Lima bean | – | Jun 1–15 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Jun 8–29 (sow outdoors) | – |
| Cucumber | Apr 20–27 | May 25–Jun 8 (transplant) May 25–Jun 8 (sow outdoors) | – |
| Summer squash / zucchini | Apr 20–27 | May 25–Jun 8 (transplant) May 25–Jun 8 (sow outdoors) | – |
| Winter squash | Apr 20–27 | May 25–Jun 8 (transplant) May 25–Jun 8 (sow outdoors) | – |
| Pumpkin | – | May 25–Jun 8 (sow outdoors) | – |
| Watermelon | Apr 20–27 | Jun 1–15 (transplant) Jun 1–15 (sow outdoors) | – |
| Cantaloupe / muskmelon | Apr 20–27 | Jun 1–15 (transplant) Jun 1–15 (sow outdoors) | – |
| Okra | Apr 6–20 | Jun 1–15 (transplant) Jun 1–15 (sow outdoors) | – |
| Celery | Feb 23–Mar 9 | May 25–Jun 1 (transplant) | – |
| Basil | Apr 6–20 | May 25–Jun 8 (transplant) May 25–Jun 8 (sow outdoors) | – |
| Cilantro | – | May 4–Jun 1 (sow outdoors) | Jul 29–Aug 12 (sowing) |
| Parsley | Mar 9–23 | May 4–18 (transplant) Apr 27–May 18 (sow outdoors) | – |
| Dill | – | May 18–Jun 1 (sow outdoors) | Jul 29–Aug 12 (sowing) |
| Sunflower | – | May 18–Jun 1 (sow outdoors) | – |
| Asparagus (crowns) | – | Apr 20–May 4 (transplant) | – |
| Rhubarb (crowns) | – | Apr 20–May 4 (transplant) | – |
| Strawberry (plants) | – | Apr 20–May 4 (transplant) | Jul 15–Aug 12 (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: Ralph 1 N, SD (NOAA GHCN-Daily ID USC00396907), elevation 2,790 ft, 3.5 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Lodgepole 5SW, SD | 13 mi | May 30 | Sep 11 |
| Ludlow 3 SSE, SD | 17 mi | May 16 | Sep 26 |
| Hettinger EXP STN, ND | 22 mi | May 21 | Sep 21 |
The average last-frost dates of these stations span 14 days, a rough guide to local variation. See data sources & methods.
Frost questions for 57650
When is the last frost in 57650?
The average (50% chance) last spring freeze of 32°F for ZIP 57650 is May 18. For a more cautious planting date, use May 31, when only 1 year in 10 still sees a later freeze.
When is the first frost in 57650?
The average first fall freeze is September 23. In 1 year in 10 it comes by September 8.
What hardiness zone is 57650?
ZIP 57650 is in USDA zone 4b (-25 to -20°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 57650 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
57755 57640 58653 Gascoyne 58649 Reeder 57651 58639 Hettinger 57649 Prairie City 58623 Bowman
Other ZIP codes in Harding County
57651 57720 57724 57755 57776 All Harding County frost dates · South Dakota frost dates
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