Fall in zone 5aPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 51034 (Mapleton, 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, Mapleton NO.2, IA (0 miles away).
- Average last spring frostMay 350% chance of a 32°F freeze after this date
- Average first fall frostOct 150% chance of a 32°F freeze by this date
- Growing season (frost-free)151 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
53°F 50–55°F
24-hour average · latest 53°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Shagbark Hills (20 mi).
4-inch depth
53°F 50–55°F
24-hour average · latest 53°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Shagbark Hills (20 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 51034 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 21 |
| 50% (the "average" last frost) | May 3 |
| 10% (cautious: only 1 year in 10 freezes later) | May 16 |
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 19 |
| 50% (the "average" first frost) | Oct 1 |
| 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 11 | Sep 24 |
| 32°F (freeze) | May 3 | Oct 1 |
| 28°F (hard freeze) | Apr 24 | 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 51034
Dates count from your average last spring frost (May 3) and first fall frost (Oct 1). 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 8–22 | May 10–24 (transplant) | – |
| Pepper (sweet and hot) | Feb 22–Mar 8 | May 17–31 (transplant) | – |
| Eggplant | Feb 22–Mar 8 | May 17–31 (transplant) | – |
| Tomatillo | Mar 8–22 | May 10–24 (transplant) | – |
| Lettuce | Mar 8–22 | Apr 12–May 3 (transplant) Apr 5–May 17 (sow outdoors) | Aug 6–27 (transplant) Jul 23–Aug 20 (sowing) |
| Spinach | – | Mar 22–Apr 12 (sow outdoors) | Aug 6–27 (sowing) |
| Kale | Mar 8–22 | Apr 5–19 (transplant) Apr 5–19 (sow outdoors) | Jul 9–Aug 6 (transplant) Jun 25–Jul 23 (sowing) |
| Collards | Mar 8–22 | Apr 5–May 3 (transplant) Apr 5–May 3 (sow outdoors) | Jul 9–Aug 6 (transplant) Jun 25–Jul 23 (sowing) |
| Broccoli | Feb 22–Mar 8 | Apr 5–19 (transplant) | Jun 25–Jul 23 (transplant) |
| Cabbage | Feb 22–Mar 8 | Apr 5–19 (transplant) | Jun 25–Jul 23 (transplant) |
| Cauliflower | Feb 22–Mar 8 | Apr 19–May 3 (transplant) | Jun 25–Jul 23 (transplant) |
| Brussels sprouts | Feb 8–22 | Apr 5–19 (transplant) | Jun 11–Jul 2 (transplant) |
| Kohlrabi | Mar 8–22 | Apr 5–19 (transplant) Apr 5–19 (sow outdoors) | Jul 23–Aug 6 (sowing) |
| Bok choy / Asian greens | – | Apr 5–19 (sow outdoors) | Aug 6–20 (sowing) |
| Arugula | – | Apr 5–May 3 (sow outdoors) | Aug 6–Sep 3 (sowing) |
| Mustard greens | – | Apr 5–26 (sow outdoors) | Aug 6–20 (sowing) |
| Swiss chard | Mar 22–Apr 5 | Apr 19–May 10 (transplant) Apr 19–May 17 (sow outdoors) | Jul 23–Aug 6 (sowing) |
| Beet | – | Apr 5–May 3 (sow outdoors) | Jul 23–Aug 6 (sowing) |
| Carrot | – | Apr 12–May 10 (sow outdoors) | Jul 9–23 (sowing) |
| Radish | – | Mar 29–May 10 (sow outdoors) | Aug 20–Sep 3 (sowing) |
| Turnip | – | Apr 5–26 (sow outdoors) | Jul 23–Aug 6 (sowing) |
| Parsnip | – | Apr 12–May 3 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 8–Apr 5 (sow outdoors) | Jul 9–23 (sowing) |
| Onion (bulbing) | Feb 8–22 | Mar 22–Apr 5 (transplant) | – |
| Green onion / scallion | – | Mar 22–Apr 19 (sow outdoors) | Jul 23–Aug 6 (sowing) |
| Leek | Feb 8–22 | Apr 5–19 (transplant) | – |
| Garlic | – | – | Aug 20–Sep 17 (sowing) |
| Shallot | – | Mar 22–Apr 5 (transplant) | Aug 20–Sep 17 (sowing) |
| Potato | – | Apr 5–19 (transplant) | Jun 11–25 (transplant) |
| Sweet potato | – | May 24–Jun 7 (transplant) | – |
| Sweet corn | – | May 10–24 (sow outdoors) | – |
| Bean, bush (snap) | – | May 10–24 (sow outdoors) | – |
| Bean, pole | – | May 10–24 (sow outdoors) | – |
| Lima bean | – | May 17–31 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | May 24–Jun 14 (sow outdoors) | – |
| Cucumber | Apr 5–12 | May 10–24 (transplant) May 10–24 (sow outdoors) | – |
| Summer squash / zucchini | Apr 5–12 | May 10–24 (transplant) May 10–24 (sow outdoors) | – |
| Winter squash | Apr 5–12 | May 10–24 (transplant) May 10–24 (sow outdoors) | – |
| Pumpkin | – | May 10–24 (sow outdoors) | – |
| Watermelon | Apr 5–12 | May 17–31 (transplant) May 17–31 (sow outdoors) | – |
| Cantaloupe / muskmelon | Apr 5–12 | May 17–31 (transplant) May 17–31 (sow outdoors) | – |
| Okra | Mar 22–Apr 5 | May 17–31 (transplant) May 17–31 (sow outdoors) | – |
| Celery | Feb 8–22 | May 10–17 (transplant) | – |
| Basil | Mar 22–Apr 5 | May 10–24 (transplant) May 10–24 (sow outdoors) | – |
| Cilantro | – | Apr 19–May 17 (sow outdoors) | Aug 6–20 (sowing) |
| Parsley | Feb 22–Mar 8 | Apr 19–May 3 (transplant) Apr 12–May 3 (sow outdoors) | – |
| Dill | – | May 3–17 (sow outdoors) | Aug 6–20 (sowing) |
| Sunflower | – | May 3–17 (sow outdoors) | – |
| Asparagus (crowns) | – | Apr 5–19 (transplant) | – |
| Rhubarb (crowns) | – | Apr 5–19 (transplant) | – |
| Strawberry (plants) | – | Apr 5–19 (transplant) | Jul 23–Aug 20 (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: Mapleton NO.2, IA (NOAA GHCN-Daily ID USC00135123), elevation 1,200 ft, 0.3 miles from the ZIP's center point. NOAA completeness flag: S (standard, 24+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Castana EXP Farm, IA | 7 mi | Apr 25 | Oct 12 |
| Battle Creek 3NE, IA | 18 mi | May 1 | Oct 1 |
| Onawa 3NW, IA | 18 mi | May 1 | Oct 3 |
The average last-frost dates of these stations span 9 days, a rough guide to local variation. See data sources & methods.
Frost questions for 51034
When is the last frost in 51034?
The average (50% chance) last spring freeze of 32°F for ZIP 51034 is May 3. For a more cautious planting date, use May 16, when only 1 year in 10 still sees a later freeze.
When is the first frost in 51034?
The average first fall freeze is October 1. In 1 year in 10 it comes by September 19.
What hardiness zone is 51034?
ZIP 51034 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 51034 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
51019 Danbury 51010 Castana 51051 Rodney 51060 Ute 51056 Smithland 51460 Ricketts 51439 Charter Oak 51044 Oto
Other ZIP codes in Monona County
51010 51040 51051 51060 51063 51523 51558 51572 All Monona County frost dates · Iowa frost dates
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Weekly yard timing, plus frost and soil-temperature alerts for your ZIP code.
- Freeze alerts
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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.