Frost dates for ZIP 51541 (Henderson, 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, Oakland, IA (12 miles away).
- Average last spring frostApr 2350% chance of a 32°F freeze after this date
- Average first fall frostOct 1450% chance of a 32°F freeze by this date
- Growing season (frost-free)174 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 17, 2026, from your frost dates, zone and soil temperature. Lawn timing · Vegetables · Pruning · Plants
Soil temperature now
2-inch depth
52°F 50–55°F
24-hour average · latest 53°F, as of Oct 17, 10:00 PM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Rogers Farm #1 (58 mi).
4-inch depth
53°F 50–55°F
24-hour average · latest 54°F, as of Oct 17, 10:00 PM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Rogers Farm #1 (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 51541 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 53°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 10 |
| 50% (the "average" last frost) | Apr 23 |
| 10% (cautious: only 1 year in 10 freezes later) | May 5 |
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 30 |
| 50% (the "average" first frost) | Oct 14 |
| 90% (late: most years have frozen by now) | Oct 27 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | May 2 | Oct 4 |
| 32°F (freeze) | Apr 23 | Oct 14 |
| 28°F (hard freeze) | Apr 15 | Oct 25 |
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 51541
Dates count from your average last spring frost (Apr 23) and first fall frost (Oct 14). 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 | Feb 26–Mar 12 | Apr 30–May 14 (transplant) | – |
| Pepper (sweet and hot) | Feb 12–26 | May 7–21 (transplant) | – |
| Eggplant | Feb 12–26 | May 7–21 (transplant) | – |
| Tomatillo | Feb 26–Mar 12 | Apr 30–May 14 (transplant) | – |
| Lettuce | Feb 26–Mar 12 | Apr 2–23 (transplant) Mar 26–May 7 (sow outdoors) | Aug 19–Sep 9 (transplant) Aug 5–Sep 2 (sowing) |
| Spinach | – | Mar 12–Apr 2 (sow outdoors) | Aug 19–Sep 9 (sowing) |
| Kale | Feb 26–Mar 12 | Mar 26–Apr 9 (transplant) Mar 26–Apr 9 (sow outdoors) | Jul 22–Aug 19 (transplant) Jul 8–Aug 5 (sowing) |
| Collards | Feb 26–Mar 12 | Mar 26–Apr 23 (transplant) Mar 26–Apr 23 (sow outdoors) | Jul 22–Aug 19 (transplant) Jul 8–Aug 5 (sowing) |
| Broccoli | Feb 12–26 | Mar 26–Apr 9 (transplant) | Jul 8–Aug 5 (transplant) |
| Cabbage | Feb 12–26 | Mar 26–Apr 9 (transplant) | Jul 8–Aug 5 (transplant) |
| Cauliflower | Feb 12–26 | Apr 9–23 (transplant) | Jul 8–Aug 5 (transplant) |
| Brussels sprouts | Jan 29–Feb 12 | Mar 26–Apr 9 (transplant) | Jun 24–Jul 15 (transplant) |
| Kohlrabi | Feb 26–Mar 12 | Mar 26–Apr 9 (transplant) Mar 26–Apr 9 (sow outdoors) | Aug 5–19 (sowing) |
| Bok choy / Asian greens | – | Mar 26–Apr 9 (sow outdoors) | Aug 19–Sep 2 (sowing) |
| Arugula | – | Mar 26–Apr 23 (sow outdoors) | Aug 19–Sep 16 (sowing) |
| Mustard greens | – | Mar 26–Apr 16 (sow outdoors) | Aug 19–Sep 2 (sowing) |
| Swiss chard | Mar 12–26 | Apr 9–30 (transplant) Apr 9–May 7 (sow outdoors) | Aug 5–19 (sowing) |
| Beet | – | Mar 26–Apr 23 (sow outdoors) | Aug 5–19 (sowing) |
| Carrot | – | Apr 2–30 (sow outdoors) | Jul 22–Aug 5 (sowing) |
| Radish | – | Mar 19–Apr 30 (sow outdoors) | Sep 2–16 (sowing) |
| Turnip | – | Mar 26–Apr 16 (sow outdoors) | Aug 5–19 (sowing) |
| Parsnip | – | Apr 2–23 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Feb 26–Mar 26 (sow outdoors) | Jul 22–Aug 5 (sowing) |
| Onion (bulbing) | Jan 29–Feb 12 | Mar 12–26 (transplant) | – |
| Green onion / scallion | – | Mar 12–Apr 9 (sow outdoors) | Aug 5–19 (sowing) |
| Leek | Jan 29–Feb 12 | Mar 26–Apr 9 (transplant) | – |
| Garlic | – | – | Sep 2–30 (sowing) |
| Shallot | – | Mar 12–26 (transplant) | Sep 2–30 (sowing) |
| Potato | – | Mar 26–Apr 9 (transplant) | Jun 24–Jul 8 (transplant) |
| Sweet potato | – | May 14–28 (transplant) | – |
| Sweet corn | – | Apr 30–May 14 (sow outdoors) | – |
| Bean, bush (snap) | – | Apr 30–May 14 (sow outdoors) | – |
| Bean, pole | – | Apr 30–May 14 (sow outdoors) | – |
| Lima bean | – | May 7–21 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | May 14–Jun 4 (sow outdoors) | – |
| Cucumber | Mar 26–Apr 2 | Apr 30–May 14 (transplant) Apr 30–May 14 (sow outdoors) | – |
| Summer squash / zucchini | Mar 26–Apr 2 | Apr 30–May 14 (transplant) Apr 30–May 14 (sow outdoors) | – |
| Winter squash | Mar 26–Apr 2 | Apr 30–May 14 (transplant) Apr 30–May 14 (sow outdoors) | – |
| Pumpkin | – | Apr 30–May 14 (sow outdoors) | – |
| Watermelon | Mar 26–Apr 2 | May 7–21 (transplant) May 7–21 (sow outdoors) | – |
| Cantaloupe / muskmelon | Mar 26–Apr 2 | May 7–21 (transplant) May 7–21 (sow outdoors) | – |
| Okra | Mar 12–26 | May 7–21 (transplant) May 7–21 (sow outdoors) | – |
| Celery | Jan 29–Feb 12 | Apr 30–May 7 (transplant) | – |
| Basil | Mar 12–26 | Apr 30–May 14 (transplant) Apr 30–May 14 (sow outdoors) | – |
| Cilantro | – | Apr 9–May 7 (sow outdoors) | Aug 19–Sep 2 (sowing) |
| Parsley | Feb 12–26 | Apr 9–23 (transplant) Apr 2–23 (sow outdoors) | – |
| Dill | – | Apr 23–May 7 (sow outdoors) | Aug 19–Sep 2 (sowing) |
| Sunflower | – | Apr 23–May 7 (sow outdoors) | – |
| Asparagus (crowns) | – | Mar 26–Apr 9 (transplant) | – |
| Rhubarb (crowns) | – | Mar 26–Apr 9 (transplant) | – |
| Strawberry (plants) | – | Mar 26–Apr 9 (transplant) | Aug 5–Sep 2 (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: Oakland, IA (NOAA GHCN-Daily ID USC00136151), elevation 1,260 ft, 11.6 miles from the ZIP's center point. NOAA completeness flag: S (standard, 24+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Red Oak, IA | 13 mi | Apr 24 | Oct 13 |
| Glenwood 3SW, IA | 21 mi | Apr 23 | Oct 11 |
| Shenandoah, IA | 26 mi | Apr 20 | Oct 17 |
The average last-frost dates of these stations span 4 days, a rough guide to local variation. See data sources & methods.
Frost questions for 51541
When is the last frost in 51541?
The average (50% chance) last spring freeze of 32°F for ZIP 51541 is April 23. For a more cautious planting date, use May 5, when only 1 year in 10 still sees a later freeze.
When is the first frost in 51541?
The average first fall freeze is October 14. In 1 year in 10 it comes by September 30.
What hardiness zone is 51541?
ZIP 51541 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 51541 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
51549 Macedonia 51525 Carson 51533 Emerson 51540 Hastings 51571 Silver City 51575 Treynor 51560 Oakland 51566 Red Oak
Other ZIP codes in Mills County
51534 51540 51551 51554 51561 51571 All Mills County frost dates · Iowa frost dates
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