Fall in zone 4aPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 58201 (Grand Forks, ND)
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, Grand Forks Univ (nws), ND (4 miles away).
- Average last spring frostMay 1050% 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)144 daysmedian, 32°F threshold
- USDA hardiness zone4a-30 to -25°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
48°F Below 50°F
24-hour average · latest 50°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Glacial Ridge (42 mi).
4-inch depth
49°F Below 50°F
24-hour average · latest 50°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Glacial Ridge (42 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 58201 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 49°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 28 |
| 50% (the "average" last frost) | May 10 |
| 10% (cautious: only 1 year in 10 freezes later) | May 24 |
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 1 |
| 90% (late: most years have frozen by now) | Oct 15 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | May 19 | Sep 23 |
| 32°F (freeze) | May 10 | Oct 1 |
| 28°F (hard freeze) | Apr 30 | 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 58201
Dates count from your average last spring frost (May 10) 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 15–29 | May 17–31 (transplant) | – |
| Pepper (sweet and hot) | Mar 1–15 | May 24–Jun 7 (transplant) | – |
| Eggplant | Mar 1–15 | May 24–Jun 7 (transplant) | – |
| Tomatillo | Mar 15–29 | May 17–31 (transplant) | – |
| Lettuce | Mar 15–29 | Apr 19–May 10 (transplant) Apr 12–May 24 (sow outdoors) | Aug 6–27 (transplant) Jul 23–Aug 20 (sowing) |
| Spinach | – | Mar 29–Apr 19 (sow outdoors) | Aug 6–27 (sowing) |
| Kale | Mar 15–29 | Apr 12–26 (transplant) Apr 12–26 (sow outdoors) | Jul 9–Aug 6 (transplant) Jun 25–Jul 23 (sowing) |
| Collards | Mar 15–29 | Apr 12–May 10 (transplant) Apr 12–May 10 (sow outdoors) | Jul 9–Aug 6 (transplant) Jun 25–Jul 23 (sowing) |
| Broccoli | Mar 1–15 | Apr 12–26 (transplant) | Jun 25–Jul 23 (transplant) |
| Cabbage | Mar 1–15 | Apr 12–26 (transplant) | Jun 25–Jul 23 (transplant) |
| Cauliflower | Mar 1–15 | Apr 26–May 10 (transplant) | Jun 25–Jul 23 (transplant) |
| Brussels sprouts | Feb 15–Mar 1 | Apr 12–26 (transplant) | Jun 11–Jul 2 (transplant) |
| Kohlrabi | Mar 15–29 | Apr 12–26 (transplant) Apr 12–26 (sow outdoors) | Jul 23–Aug 6 (sowing) |
| Bok choy / Asian greens | – | Apr 12–26 (sow outdoors) | Aug 6–20 (sowing) |
| Arugula | – | Apr 12–May 10 (sow outdoors) | Aug 6–Sep 3 (sowing) |
| Mustard greens | – | Apr 12–May 3 (sow outdoors) | Aug 6–20 (sowing) |
| Swiss chard | Mar 29–Apr 12 | Apr 26–May 17 (transplant) Apr 26–May 24 (sow outdoors) | Jul 23–Aug 6 (sowing) |
| Beet | – | Apr 12–May 10 (sow outdoors) | Jul 23–Aug 6 (sowing) |
| Carrot | – | Apr 19–May 17 (sow outdoors) | Jul 9–23 (sowing) |
| Radish | – | Apr 5–May 17 (sow outdoors) | Aug 20–Sep 3 (sowing) |
| Turnip | – | Apr 12–May 3 (sow outdoors) | Jul 23–Aug 6 (sowing) |
| Parsnip | – | Apr 19–May 10 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 15–Apr 12 (sow outdoors) | Jul 9–23 (sowing) |
| Onion (bulbing) | Feb 15–Mar 1 | Mar 29–Apr 12 (transplant) | – |
| Green onion / scallion | – | Mar 29–Apr 26 (sow outdoors) | Jul 23–Aug 6 (sowing) |
| Leek | Feb 15–Mar 1 | Apr 12–26 (transplant) | – |
| Garlic | – | – | Aug 20–Sep 17 (sowing) |
| Shallot | – | Mar 29–Apr 12 (transplant) | Aug 20–Sep 17 (sowing) |
| Potato | – | Apr 12–26 (transplant) | Jun 11–25 (transplant) |
| Sweet potato | – | May 31–Jun 14 (transplant) | – |
| Sweet corn | – | May 17–31 (sow outdoors) | – |
| Bean, bush (snap) | – | May 17–31 (sow outdoors) | – |
| Bean, pole | – | May 17–31 (sow outdoors) | – |
| Lima bean | – | May 24–Jun 7 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | May 31–Jun 21 (sow outdoors) | – |
| Cucumber | Apr 12–19 | May 17–31 (transplant) May 17–31 (sow outdoors) | – |
| Summer squash / zucchini | Apr 12–19 | May 17–31 (transplant) May 17–31 (sow outdoors) | – |
| Winter squash | Apr 12–19 | May 17–31 (transplant) May 17–31 (sow outdoors) | – |
| Pumpkin | – | May 17–31 (sow outdoors) | – |
| Watermelon | Apr 12–19 | May 24–Jun 7 (transplant) May 24–Jun 7 (sow outdoors) | – |
| Cantaloupe / muskmelon | Apr 12–19 | May 24–Jun 7 (transplant) May 24–Jun 7 (sow outdoors) | – |
| Okra | Mar 29–Apr 12 | May 24–Jun 7 (transplant) May 24–Jun 7 (sow outdoors) | – |
| Celery | Feb 15–Mar 1 | May 17–24 (transplant) | – |
| Basil | Mar 29–Apr 12 | May 17–31 (transplant) May 17–31 (sow outdoors) | – |
| Cilantro | – | Apr 26–May 24 (sow outdoors) | Aug 6–20 (sowing) |
| Parsley | Mar 1–15 | Apr 26–May 10 (transplant) Apr 19–May 10 (sow outdoors) | – |
| Dill | – | May 10–24 (sow outdoors) | Aug 6–20 (sowing) |
| Sunflower | – | May 10–24 (sow outdoors) | – |
| Asparagus (crowns) | – | Apr 12–26 (transplant) | – |
| Rhubarb (crowns) | – | Apr 12–26 (transplant) | – |
| Strawberry (plants) | – | Apr 12–26 (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: Grand Forks Univ (nws), ND (NOAA GHCN-Daily ID USC00323621), elevation 830 ft, 4.3 miles from the ZIP's center point. NOAA completeness flag: S (standard, 24+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Grand Forks Intl AP, ND | 6 mi | May 16 | Sep 27 |
| Crookston NW EXP STN, MN | 25 mi | May 11 | Sep 27 |
| Larimore 4SW, ND | 26 mi | May 11 | Sep 28 |
The average last-frost dates of these stations span 6 days, a rough guide to local variation. See data sources & methods.
Frost questions for 58201
When is the last frost in 58201?
The average (50% chance) last spring freeze of 32°F for ZIP 58201 is May 10. For a more cautious planting date, use May 24, when only 1 year in 10 still sees a later freeze.
When is the first frost in 58201?
The average first fall freeze is October 1. In 1 year in 10 it comes by September 20.
What hardiness zone is 58201?
ZIP 58201 is in USDA zone 4a (-30 to -25°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 58201 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
58202 Grand Forks 58278 Thompson 58203 Grand Forks 58228 Emerado 56721 East Grand Forks 58275 Reynolds 58204 Grand Forks AFB 58205 Grand Forks AFB
Other ZIP codes in Grand Forks County
58202 58203 58204 58205 58214 58228 58235 58244 58251 58256 58258 58266 58267 58275 58278 All Grand Forks County frost dates · North Dakota frost dates
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Weekly yard timing, plus frost and soil-temperature alerts for your ZIP code.
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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.