Fall in zone 3aPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 56668 (Ranier, 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, Intl Falls Intl AP, MN (4 miles away).
- Average last spring frostMay 2950% chance of a 32°F freeze after this date
- Average first fall frostSep 1350% chance of a 32°F freeze by this date
- Growing season (frost-free)109 daysmedian, 32°F threshold
- USDA hardiness zone3a-40 to -35°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
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 56668 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) | May 13 |
| 50% (the "average" last frost) | May 29 |
| 10% (cautious: only 1 year in 10 freezes later) | Jun 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) | Aug 30 |
| 50% (the "average" first frost) | Sep 13 |
| 90% (late: most years have frozen by now) | Sep 28 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | n/a | n/a |
| 32°F (freeze) | May 29 | Sep 13 |
| 28°F (hard freeze) | May 14 | Sep 26 |
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 56668
Dates count from your average last spring frost (May 29) and first fall frost (Sep 13). 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 | Apr 3–17 | Jun 5–19 (transplant) | – |
| Pepper (sweet and hot) | Mar 20–Apr 3 | Jun 12–26 (transplant) | – |
| Eggplant | Mar 20–Apr 3 | Jun 12–26 (transplant) | – |
| Tomatillo | Apr 3–17 | Jun 5–19 (transplant) | – |
| Lettuce | Apr 3–17 | May 8–29 (transplant) May 1–Jun 12 (sow outdoors) | Jul 19–Aug 9 (transplant) Jul 5–Aug 2 (sowing) |
| Spinach | – | Apr 17–May 8 (sow outdoors) | Jul 19–Aug 9 (sowing) |
| Kale | Apr 3–17 | May 1–15 (transplant) May 1–15 (sow outdoors) | Jun 21–Jul 19 (transplant) Jun 7–Jul 5 (sowing) |
| Collards | Apr 3–17 | May 1–29 (transplant) May 1–29 (sow outdoors) | Jun 21–Jul 19 (transplant) Jun 7–Jul 5 (sowing) |
| Broccoli | Mar 20–Apr 3 | May 1–15 (transplant) | Jun 7–Jul 5 (transplant) |
| Cabbage | Mar 20–Apr 3 | May 1–15 (transplant) | Jun 7–Jul 5 (transplant) |
| Cauliflower | Mar 20–Apr 3 | May 15–29 (transplant) | Jun 7–Jul 5 (transplant) |
| Brussels sprouts | Mar 6–20 | May 1–15 (transplant) | May 24–Jun 14 (transplant) |
| Kohlrabi | Apr 3–17 | May 1–15 (transplant) May 1–15 (sow outdoors) | Jul 5–19 (sowing) |
| Bok choy / Asian greens | – | May 1–15 (sow outdoors) | Jul 19–Aug 2 (sowing) |
| Arugula | – | May 1–29 (sow outdoors) | Jul 19–Aug 16 (sowing) |
| Mustard greens | – | May 1–22 (sow outdoors) | Jul 19–Aug 2 (sowing) |
| Swiss chard | Apr 17–May 1 | May 15–Jun 5 (transplant) May 15–Jun 12 (sow outdoors) | Jul 5–19 (sowing) |
| Beet | – | May 1–29 (sow outdoors) | Jul 5–19 (sowing) |
| Carrot | – | May 8–Jun 5 (sow outdoors) | Jun 21–Jul 5 (sowing) |
| Radish | – | Apr 24–Jun 5 (sow outdoors) | Aug 2–16 (sowing) |
| Turnip | – | May 1–22 (sow outdoors) | Jul 5–19 (sowing) |
| Parsnip | – | May 8–29 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Apr 3–May 1 (sow outdoors) | Jun 21–Jul 5 (sowing) |
| Onion (bulbing) | Mar 6–20 | Apr 17–May 1 (transplant) | – |
| Green onion / scallion | – | Apr 17–May 15 (sow outdoors) | Jul 5–19 (sowing) |
| Leek | Mar 6–20 | May 1–15 (transplant) | – |
| Garlic | – | – | Aug 2–30 (sowing) |
| Shallot | – | Apr 17–May 1 (transplant) | Aug 2–30 (sowing) |
| Potato | – | May 1–15 (transplant) | May 24–Jun 7 (transplant) |
| Sweet potato | – | Jun 19–Jul 3 (transplant) | – |
| Sweet corn | – | Jun 5–19 (sow outdoors) | – |
| Bean, bush (snap) | – | Jun 5–19 (sow outdoors) | – |
| Bean, pole | – | Jun 5–19 (sow outdoors) | – |
| Lima bean | – | Jun 12–26 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Jun 19–Jul 10 (sow outdoors) | – |
| Cucumber | May 1–8 | Jun 5–19 (transplant) Jun 5–19 (sow outdoors) | – |
| Summer squash / zucchini | May 1–8 | Jun 5–19 (transplant) Jun 5–19 (sow outdoors) | – |
| Winter squash | May 1–8 | Jun 5–19 (transplant) Jun 5–19 (sow outdoors) | – |
| Pumpkin | – | Jun 5–19 (sow outdoors) | – |
| Watermelon | May 1–8 | Jun 12–26 (transplant) Jun 12–26 (sow outdoors) | – |
| Cantaloupe / muskmelon | May 1–8 | Jun 12–26 (transplant) Jun 12–26 (sow outdoors) | – |
| Okra | Apr 17–May 1 | Jun 12–26 (transplant) Jun 12–26 (sow outdoors) | – |
| Celery | Mar 6–20 | Jun 5–12 (transplant) | – |
| Basil | Apr 17–May 1 | Jun 5–19 (transplant) Jun 5–19 (sow outdoors) | – |
| Cilantro | – | May 15–Jun 12 (sow outdoors) | Jul 19–Aug 2 (sowing) |
| Parsley | Mar 20–Apr 3 | May 15–29 (transplant) May 8–29 (sow outdoors) | – |
| Dill | – | May 29–Jun 12 (sow outdoors) | Jul 19–Aug 2 (sowing) |
| Sunflower | – | May 29–Jun 12 (sow outdoors) | – |
| Asparagus (crowns) | – | May 1–15 (transplant) | – |
| Rhubarb (crowns) | – | May 1–15 (transplant) | – |
| Strawberry (plants) | – | May 1–15 (transplant) | Jul 5–Aug 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: Intl Falls Intl AP, MN (NOAA GHCN-Daily ID USW00014918), elevation 1,183 ft, 4.4 miles from the ZIP's center point. NOAA completeness flag: S (standard, 24+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Kabetogama, MN | 20 mi | May 28 | Sep 16 |
| Littlefork 10 SW, MN | 24 mi | May 23 | Sep 21 |
| Big Falls, MN | 36 mi | May 24 | Sep 20 |
The average last-frost dates of these stations span 6 days, a rough guide to local variation. See data sources & methods.
Frost questions for 56668
When is the last frost in 56668?
The average (50% chance) last spring freeze of 32°F for ZIP 56668 is May 29. For a more cautious planting date, use June 16, when only 1 year in 10 still sees a later freeze.
When is the first frost in 56668?
The average first fall freeze is September 13. In 1 year in 10 it comes by August 30.
What hardiness zone is 56668?
ZIP 56668 is in USDA zone 3a (-40 to -35°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 56668 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
56649 International Falls 56669 56653 Littlefork 56654 55772 Nett Lake 56629 55771 Nett Lake 55725
Other ZIP codes in Koochiching County
55772 56627 56629 56649 56653 56654 56658 56660 56661 56669 All Koochiching County frost dates · Minnesota frost dates
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- 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.