Fall in zone 5aPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 51238 (Hospers, IA)
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, Sheldon, IA (8 miles away).
- Average last spring frostMay 550% chance of a 32°F freeze after this date
- Average first fall frostSep 2850% chance of a 32°F freeze by this date
- Growing season (frost-free)145 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
51°F 50–55°F
24-hour average · latest 51°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Shagbark Hills (44 mi), Sioux Falls 14 NNE (58 mi), Eros Data Center (58 mi).
4-inch depth
52°F 50–55°F
24-hour average · latest 52°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Shagbark Hills (44 mi), Sioux Falls 14 NNE (58 mi), Eros Data Center (58 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 51238 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 52°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 24 |
| 50% (the "average" last frost) | May 5 |
| 10% (cautious: only 1 year in 10 freezes later) | May 18 |
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 14 |
| 50% (the "average" first frost) | Sep 28 |
| 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 13 | Sep 20 |
| 32°F (freeze) | May 5 | Sep 28 |
| 28°F (hard freeze) | Apr 28 | Oct 6 |
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 51238
Dates count from your average last spring frost (May 5) and first fall frost (Sep 28). 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 10–24 | May 12–26 (transplant) | – |
| Pepper (sweet and hot) | Feb 24–Mar 10 | May 19–Jun 2 (transplant) | – |
| Eggplant | Feb 24–Mar 10 | May 19–Jun 2 (transplant) | – |
| Tomatillo | Mar 10–24 | May 12–26 (transplant) | – |
| Lettuce | Mar 10–24 | Apr 14–May 5 (transplant) Apr 7–May 19 (sow outdoors) | Aug 3–24 (transplant) Jul 20–Aug 17 (sowing) |
| Spinach | – | Mar 24–Apr 14 (sow outdoors) | Aug 3–24 (sowing) |
| Kale | Mar 10–24 | Apr 7–21 (transplant) Apr 7–21 (sow outdoors) | Jul 6–Aug 3 (transplant) Jun 22–Jul 20 (sowing) |
| Collards | Mar 10–24 | Apr 7–May 5 (transplant) Apr 7–May 5 (sow outdoors) | Jul 6–Aug 3 (transplant) Jun 22–Jul 20 (sowing) |
| Broccoli | Feb 24–Mar 10 | Apr 7–21 (transplant) | Jun 22–Jul 20 (transplant) |
| Cabbage | Feb 24–Mar 10 | Apr 7–21 (transplant) | Jun 22–Jul 20 (transplant) |
| Cauliflower | Feb 24–Mar 10 | Apr 21–May 5 (transplant) | Jun 22–Jul 20 (transplant) |
| Brussels sprouts | Feb 10–24 | Apr 7–21 (transplant) | Jun 8–29 (transplant) |
| Kohlrabi | Mar 10–24 | Apr 7–21 (transplant) Apr 7–21 (sow outdoors) | Jul 20–Aug 3 (sowing) |
| Bok choy / Asian greens | – | Apr 7–21 (sow outdoors) | Aug 3–17 (sowing) |
| Arugula | – | Apr 7–May 5 (sow outdoors) | Aug 3–31 (sowing) |
| Mustard greens | – | Apr 7–28 (sow outdoors) | Aug 3–17 (sowing) |
| Swiss chard | Mar 24–Apr 7 | Apr 21–May 12 (transplant) Apr 21–May 19 (sow outdoors) | Jul 20–Aug 3 (sowing) |
| Beet | – | Apr 7–May 5 (sow outdoors) | Jul 20–Aug 3 (sowing) |
| Carrot | – | Apr 14–May 12 (sow outdoors) | Jul 6–20 (sowing) |
| Radish | – | Mar 31–May 12 (sow outdoors) | Aug 17–31 (sowing) |
| Turnip | – | Apr 7–28 (sow outdoors) | Jul 20–Aug 3 (sowing) |
| Parsnip | – | Apr 14–May 5 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 10–Apr 7 (sow outdoors) | Jul 6–20 (sowing) |
| Onion (bulbing) | Feb 10–24 | Mar 24–Apr 7 (transplant) | – |
| Green onion / scallion | – | Mar 24–Apr 21 (sow outdoors) | Jul 20–Aug 3 (sowing) |
| Leek | Feb 10–24 | Apr 7–21 (transplant) | – |
| Garlic | – | – | Aug 17–Sep 14 (sowing) |
| Shallot | – | Mar 24–Apr 7 (transplant) | Aug 17–Sep 14 (sowing) |
| Potato | – | Apr 7–21 (transplant) | Jun 8–22 (transplant) |
| Sweet potato | – | May 26–Jun 9 (transplant) | – |
| Sweet corn | – | May 12–26 (sow outdoors) | – |
| Bean, bush (snap) | – | May 12–26 (sow outdoors) | – |
| Bean, pole | – | May 12–26 (sow outdoors) | – |
| Lima bean | – | May 19–Jun 2 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | May 26–Jun 16 (sow outdoors) | – |
| Cucumber | Apr 7–14 | May 12–26 (transplant) May 12–26 (sow outdoors) | – |
| Summer squash / zucchini | Apr 7–14 | May 12–26 (transplant) May 12–26 (sow outdoors) | – |
| Winter squash | Apr 7–14 | May 12–26 (transplant) May 12–26 (sow outdoors) | – |
| Pumpkin | – | May 12–26 (sow outdoors) | – |
| Watermelon | Apr 7–14 | May 19–Jun 2 (transplant) May 19–Jun 2 (sow outdoors) | – |
| Cantaloupe / muskmelon | Apr 7–14 | May 19–Jun 2 (transplant) May 19–Jun 2 (sow outdoors) | – |
| Okra | Mar 24–Apr 7 | May 19–Jun 2 (transplant) May 19–Jun 2 (sow outdoors) | – |
| Celery | Feb 10–24 | May 12–19 (transplant) | – |
| Basil | Mar 24–Apr 7 | May 12–26 (transplant) May 12–26 (sow outdoors) | – |
| Cilantro | – | Apr 21–May 19 (sow outdoors) | Aug 3–17 (sowing) |
| Parsley | Feb 24–Mar 10 | Apr 21–May 5 (transplant) Apr 14–May 5 (sow outdoors) | – |
| Dill | – | May 5–19 (sow outdoors) | Aug 3–17 (sowing) |
| Sunflower | – | May 5–19 (sow outdoors) | – |
| Asparagus (crowns) | – | Apr 7–21 (transplant) | – |
| Rhubarb (crowns) | – | Apr 7–21 (transplant) | – |
| Strawberry (plants) | – | Apr 7–21 (transplant) | Jul 20–Aug 17 (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: Sheldon, IA (NOAA GHCN-Daily ID USC00137594), elevation 1,420 ft, 7.6 miles from the ZIP's center point. NOAA completeness flag: S (standard, 24+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Sioux Ctr 2 SE, IA | 13 mi | Apr 30 | Oct 3 |
| Primghar, IA | 13 mi | Apr 29 | Oct 10 |
| Sanborn, IA | 14 mi | May 1 | Oct 7 |
The average last-frost dates of these stations span 7 days, a rough guide to local variation. See data sources & methods.
Frost questions for 51238
When is the last frost in 51238?
The average (50% chance) last spring freeze of 32°F for ZIP 51238 is May 5. For a more cautious planting date, use May 18, when only 1 year in 10 still sees a later freeze.
When is the first frost in 51238?
The average first fall freeze is September 28. In 1 year in 10 it comes by September 14.
What hardiness zone is 51238?
ZIP 51238 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 51238 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
51022 Granville 51003 Alton 51201 Sheldon 51231 Archer 51041 Orange City 51234 Boyden 51244 Matlock 51046 Paullina
Other ZIP codes in Sioux County
51003 51011 51023 51027 51036 51041 51201 51234 51239 51244 51247 51250 All Sioux County frost dates · Iowa frost dates
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Weekly yard timing, plus frost and soil-temperature alerts for your ZIP code.
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