Fall in zone 3bPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 56637 (Itasca County, MN)
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, Marcell 5NE, MN (9 miles away).
- Average last spring frostMay 1450% chance of a 32°F freeze after this date
- Average first fall frostOct 250% chance of a 32°F freeze by this date
- Growing season (frost-free)140 daysmedian, 32°F threshold
- USDA hardiness zone3b-35 to -30°F avg. coldest night
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Frost and freeze alerts from the NWS forecast for 56637, the spring soil-temperature heads-up for pre-emergent, and a short weekly yard-timing email.
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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
No soil station with a fresh reading within 62 miles.
4-inch depth
No soil station with a fresh reading within 62 miles.
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 56637 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
No soil reading near this ZIP. Typical extension timing for your region: spring 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 30 |
| 50% (the "average" last frost) | May 14 |
| 10% (cautious: only 1 year in 10 freezes later) | May 30 |
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 20 |
| 50% (the "average" first frost) | Oct 2 |
| 90% (late: most years have frozen by now) | Oct 16 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | May 25 | Sep 24 |
| 32°F (freeze) | May 14 | Oct 2 |
| 28°F (hard freeze) | May 3 | Oct 14 |
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 56637
Dates count from your average last spring frost (May 14) and first fall frost (Oct 2). 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 19–Apr 2 | May 21–Jun 4 (transplant) | – |
| Pepper (sweet and hot) | Mar 5–19 | May 28–Jun 11 (transplant) | – |
| Eggplant | Mar 5–19 | May 28–Jun 11 (transplant) | – |
| Tomatillo | Mar 19–Apr 2 | May 21–Jun 4 (transplant) | – |
| Lettuce | Mar 19–Apr 2 | Apr 23–May 14 (transplant) Apr 16–May 28 (sow outdoors) | Aug 7–28 (transplant) Jul 24–Aug 21 (sowing) |
| Spinach | – | Apr 2–23 (sow outdoors) | Aug 7–28 (sowing) |
| Kale | Mar 19–Apr 2 | Apr 16–30 (transplant) Apr 16–30 (sow outdoors) | Jul 10–Aug 7 (transplant) Jun 26–Jul 24 (sowing) |
| Collards | Mar 19–Apr 2 | Apr 16–May 14 (transplant) Apr 16–May 14 (sow outdoors) | Jul 10–Aug 7 (transplant) Jun 26–Jul 24 (sowing) |
| Broccoli | Mar 5–19 | Apr 16–30 (transplant) | Jun 26–Jul 24 (transplant) |
| Cabbage | Mar 5–19 | Apr 16–30 (transplant) | Jun 26–Jul 24 (transplant) |
| Cauliflower | Mar 5–19 | Apr 30–May 14 (transplant) | Jun 26–Jul 24 (transplant) |
| Brussels sprouts | Feb 19–Mar 5 | Apr 16–30 (transplant) | Jun 12–Jul 3 (transplant) |
| Kohlrabi | Mar 19–Apr 2 | Apr 16–30 (transplant) Apr 16–30 (sow outdoors) | Jul 24–Aug 7 (sowing) |
| Bok choy / Asian greens | – | Apr 16–30 (sow outdoors) | Aug 7–21 (sowing) |
| Arugula | – | Apr 16–May 14 (sow outdoors) | Aug 7–Sep 4 (sowing) |
| Mustard greens | – | Apr 16–May 7 (sow outdoors) | Aug 7–21 (sowing) |
| Swiss chard | Apr 2–16 | Apr 30–May 21 (transplant) Apr 30–May 28 (sow outdoors) | Jul 24–Aug 7 (sowing) |
| Beet | – | Apr 16–May 14 (sow outdoors) | Jul 24–Aug 7 (sowing) |
| Carrot | – | Apr 23–May 21 (sow outdoors) | Jul 10–24 (sowing) |
| Radish | – | Apr 9–May 21 (sow outdoors) | Aug 21–Sep 4 (sowing) |
| Turnip | – | Apr 16–May 7 (sow outdoors) | Jul 24–Aug 7 (sowing) |
| Parsnip | – | Apr 23–May 14 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 19–Apr 16 (sow outdoors) | Jul 10–24 (sowing) |
| Onion (bulbing) | Feb 19–Mar 5 | Apr 2–16 (transplant) | – |
| Green onion / scallion | – | Apr 2–30 (sow outdoors) | Jul 24–Aug 7 (sowing) |
| Leek | Feb 19–Mar 5 | Apr 16–30 (transplant) | – |
| Garlic | – | – | Aug 21–Sep 18 (sowing) |
| Shallot | – | Apr 2–16 (transplant) | Aug 21–Sep 18 (sowing) |
| Potato | – | Apr 16–30 (transplant) | Jun 12–26 (transplant) |
| Sweet potato | – | Jun 4–18 (transplant) | – |
| Sweet corn | – | May 21–Jun 4 (sow outdoors) | – |
| Bean, bush (snap) | – | May 21–Jun 4 (sow outdoors) | – |
| Bean, pole | – | May 21–Jun 4 (sow outdoors) | – |
| Lima bean | – | May 28–Jun 11 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Jun 4–25 (sow outdoors) | – |
| Cucumber | Apr 16–23 | May 21–Jun 4 (transplant) May 21–Jun 4 (sow outdoors) | – |
| Summer squash / zucchini | Apr 16–23 | May 21–Jun 4 (transplant) May 21–Jun 4 (sow outdoors) | – |
| Winter squash | Apr 16–23 | May 21–Jun 4 (transplant) May 21–Jun 4 (sow outdoors) | – |
| Pumpkin | – | May 21–Jun 4 (sow outdoors) | – |
| Watermelon | Apr 16–23 | May 28–Jun 11 (transplant) May 28–Jun 11 (sow outdoors) | – |
| Cantaloupe / muskmelon | Apr 16–23 | May 28–Jun 11 (transplant) May 28–Jun 11 (sow outdoors) | – |
| Okra | Apr 2–16 | May 28–Jun 11 (transplant) May 28–Jun 11 (sow outdoors) | – |
| Celery | Feb 19–Mar 5 | May 21–28 (transplant) | – |
| Basil | Apr 2–16 | May 21–Jun 4 (transplant) May 21–Jun 4 (sow outdoors) | – |
| Cilantro | – | Apr 30–May 28 (sow outdoors) | Aug 7–21 (sowing) |
| Parsley | Mar 5–19 | Apr 30–May 14 (transplant) Apr 23–May 14 (sow outdoors) | – |
| Dill | – | May 14–28 (sow outdoors) | Aug 7–21 (sowing) |
| Sunflower | – | May 14–28 (sow outdoors) | – |
| Asparagus (crowns) | – | Apr 16–30 (transplant) | – |
| Rhubarb (crowns) | – | Apr 16–30 (transplant) | – |
| Strawberry (plants) | – | Apr 16–30 (transplant) | Jul 24–Aug 21 (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: Marcell 5NE, MN (NOAA GHCN-Daily ID USC00215175), elevation 1,387 ft, 8.9 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Northome 3S, MN | 24 mi | May 16 | Sep 26 |
| Pokegama Dam, MN | 28 mi | May 16 | Oct 1 |
| Grand Rpds Forest Lab, MN | 31 mi | May 17 | Sep 24 |
The average last-frost dates of these stations span 3 days, a rough guide to local variation. See data sources & methods.
Frost questions for 56637
When is the last frost in 56637?
The average (50% chance) last spring freeze of 32°F for ZIP 56637 is May 14. For a more cautious planting date, use May 30, when only 1 year in 10 still sees a later freeze.
When is the first frost in 56637?
The average first fall freeze is October 2. In 1 year in 10 it comes by September 20.
What hardiness zone is 56637?
ZIP 56637 is in USDA zone 3b (-35 to -30°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 56637 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
56680 56657 56659 56688 56628 Bigfork 56636 Ball Club 56661 Mizpah 56681 Squaw Lake
Other ZIP codes in Itasca County
55709 55716 55721 55722 55742 55744 55753 55764 55769 55775 55781 55784 55786 55793 56628 56636 56639 56657 56659 56680 56681 56688 All Itasca County frost dates · Minnesota 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.