Fall in zone 4aPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 57426 (Brown 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, Columbia 8 N, SD (9 miles away).
- Average last spring frostMay 750% chance of a 32°F freeze after this date
- Average first fall frostSep 2950% chance of a 32°F freeze by this date
- Growing season (frost-free)145 daysmedian, 32°F threshold
- USDA hardiness zone4a-30 to -25°F avg. coldest night
Get The Dial for 57426
Frost and freeze alerts from the NWS forecast for 57426, the spring soil-temperature heads-up for pre-emergent, and a short weekly yard-timing email.
- Freeze alerts
- Soil-temp heads-up
- 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.
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
49°F Below 50°F
24-hour average · latest 50°F, as of Oct 18, 1:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Aberdeen 35 WNW (31 mi).
4-inch depth
50°F Below 50°F
24-hour average · latest 50°F, as of Oct 18, 1:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Aberdeen 35 WNW (31 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 57426 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 50°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 26 |
| 50% (the "average" last frost) | May 7 |
| 10% (cautious: only 1 year in 10 freezes later) | May 22 |
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 18 |
| 50% (the "average" first frost) | Sep 29 |
| 90% (late: most years have frozen by now) | Oct 12 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | May 18 | Sep 22 |
| 32°F (freeze) | May 7 | Sep 29 |
| 28°F (hard freeze) | Apr 28 | Oct 7 |
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 57426
Dates count from your average last spring frost (May 7) and first fall frost (Sep 29). 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 12–26 | May 14–28 (transplant) | – |
| Pepper (sweet and hot) | Feb 26–Mar 12 | May 21–Jun 4 (transplant) | – |
| Eggplant | Feb 26–Mar 12 | May 21–Jun 4 (transplant) | – |
| Tomatillo | Mar 12–26 | May 14–28 (transplant) | – |
| Lettuce | Mar 12–26 | Apr 16–May 7 (transplant) Apr 9–May 21 (sow outdoors) | Aug 4–25 (transplant) Jul 21–Aug 18 (sowing) |
| Spinach | – | Mar 26–Apr 16 (sow outdoors) | Aug 4–25 (sowing) |
| Kale | Mar 12–26 | Apr 9–23 (transplant) Apr 9–23 (sow outdoors) | Jul 7–Aug 4 (transplant) Jun 23–Jul 21 (sowing) |
| Collards | Mar 12–26 | Apr 9–May 7 (transplant) Apr 9–May 7 (sow outdoors) | Jul 7–Aug 4 (transplant) Jun 23–Jul 21 (sowing) |
| Broccoli | Feb 26–Mar 12 | Apr 9–23 (transplant) | Jun 23–Jul 21 (transplant) |
| Cabbage | Feb 26–Mar 12 | Apr 9–23 (transplant) | Jun 23–Jul 21 (transplant) |
| Cauliflower | Feb 26–Mar 12 | Apr 23–May 7 (transplant) | Jun 23–Jul 21 (transplant) |
| Brussels sprouts | Feb 12–26 | Apr 9–23 (transplant) | Jun 9–30 (transplant) |
| Kohlrabi | Mar 12–26 | Apr 9–23 (transplant) Apr 9–23 (sow outdoors) | Jul 21–Aug 4 (sowing) |
| Bok choy / Asian greens | – | Apr 9–23 (sow outdoors) | Aug 4–18 (sowing) |
| Arugula | – | Apr 9–May 7 (sow outdoors) | Aug 4–Sep 1 (sowing) |
| Mustard greens | – | Apr 9–30 (sow outdoors) | Aug 4–18 (sowing) |
| Swiss chard | Mar 26–Apr 9 | Apr 23–May 14 (transplant) Apr 23–May 21 (sow outdoors) | Jul 21–Aug 4 (sowing) |
| Beet | – | Apr 9–May 7 (sow outdoors) | Jul 21–Aug 4 (sowing) |
| Carrot | – | Apr 16–May 14 (sow outdoors) | Jul 7–21 (sowing) |
| Radish | – | Apr 2–May 14 (sow outdoors) | Aug 18–Sep 1 (sowing) |
| Turnip | – | Apr 9–30 (sow outdoors) | Jul 21–Aug 4 (sowing) |
| Parsnip | – | Apr 16–May 7 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 12–Apr 9 (sow outdoors) | Jul 7–21 (sowing) |
| Onion (bulbing) | Feb 12–26 | Mar 26–Apr 9 (transplant) | – |
| Green onion / scallion | – | Mar 26–Apr 23 (sow outdoors) | Jul 21–Aug 4 (sowing) |
| Leek | Feb 12–26 | Apr 9–23 (transplant) | – |
| Garlic | – | – | Aug 18–Sep 15 (sowing) |
| Shallot | – | Mar 26–Apr 9 (transplant) | Aug 18–Sep 15 (sowing) |
| Potato | – | Apr 9–23 (transplant) | Jun 9–23 (transplant) |
| Sweet potato | – | May 28–Jun 11 (transplant) | – |
| Sweet corn | – | May 14–28 (sow outdoors) | – |
| Bean, bush (snap) | – | May 14–28 (sow outdoors) | – |
| Bean, pole | – | May 14–28 (sow outdoors) | – |
| Lima bean | – | May 21–Jun 4 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | May 28–Jun 18 (sow outdoors) | – |
| Cucumber | Apr 9–16 | May 14–28 (transplant) May 14–28 (sow outdoors) | – |
| Summer squash / zucchini | Apr 9–16 | May 14–28 (transplant) May 14–28 (sow outdoors) | – |
| Winter squash | Apr 9–16 | May 14–28 (transplant) May 14–28 (sow outdoors) | – |
| Pumpkin | – | May 14–28 (sow outdoors) | – |
| Watermelon | Apr 9–16 | May 21–Jun 4 (transplant) May 21–Jun 4 (sow outdoors) | – |
| Cantaloupe / muskmelon | Apr 9–16 | May 21–Jun 4 (transplant) May 21–Jun 4 (sow outdoors) | – |
| Okra | Mar 26–Apr 9 | May 21–Jun 4 (transplant) May 21–Jun 4 (sow outdoors) | – |
| Celery | Feb 12–26 | May 14–21 (transplant) | – |
| Basil | Mar 26–Apr 9 | May 14–28 (transplant) May 14–28 (sow outdoors) | – |
| Cilantro | – | Apr 23–May 21 (sow outdoors) | Aug 4–18 (sowing) |
| Parsley | Feb 26–Mar 12 | Apr 23–May 7 (transplant) Apr 16–May 7 (sow outdoors) | – |
| Dill | – | May 7–21 (sow outdoors) | Aug 4–18 (sowing) |
| Sunflower | – | May 7–21 (sow outdoors) | – |
| Asparagus (crowns) | – | Apr 9–23 (transplant) | – |
| Rhubarb (crowns) | – | Apr 9–23 (transplant) | – |
| Strawberry (plants) | – | Apr 9–23 (transplant) | Jul 21–Aug 18 (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: Columbia 8 N, SD (NOAA GHCN-Daily ID USC00391873), elevation 1,305 ft, 9.2 miles from the ZIP's center point. NOAA completeness flag: S (standard, 24+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Ellendale, ND | 19 mi | May 4 | Oct 2 |
| Aberdeen, SD | 20 mi | May 9 | Sep 26 |
| Aberdeen 3 E, SD | 20 mi | May 8 | Sep 29 |
The average last-frost dates of these stations span 5 days, a rough guide to local variation. See data sources & methods.
Frost questions for 57426
When is the last frost in 57426?
The average (50% chance) last spring freeze of 32°F for ZIP 57426 is May 7. For a more cautious planting date, use May 22, when only 1 year in 10 still sees a later freeze.
When is the first frost in 57426?
The average first fall freeze is September 29. In 1 year in 10 it comes by September 18.
What hardiness zone is 57426?
ZIP 57426 is in USDA zone 4a (-30 to -25°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 57426 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
57441 Frederick 57481 Long Lake Colony 57433 Columbia 57449 57401 Aberdeen 57446 Hecla 57427 Bath 57432 Newport Colony
Other ZIP codes in Brown County
57401 57427 57432 57433 57439 57441 57445 57446 57449 57460 57474 57479 57481 All Brown County frost dates · South Dakota frost dates
Never miss a frost: get The Dial
Weekly yard timing, plus frost and soil-temperature alerts for your ZIP code.
- Freeze alerts
- Soil-temp heads-up
- 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.