Fall in zone 4aPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 59435 (Toole County, MT)
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, Shelby, MT (10 miles away).
- Average last spring frostMay 2350% chance of a 32°F freeze after this date
- Average first fall frostSep 1650% chance of a 32°F freeze by this date
- Growing season (frost-free)115 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
46°F Below 50°F
24-hour average · latest 45°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Conrad Ag Rc (20 mi), Violett (40 mi).
4-inch depth
46°F Below 50°F
24-hour average · latest 47°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Conrad Ag Rc (20 mi), Violett (40 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 59435 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 46°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 mid-May).
Fertilizer window
Lawn region: Mountain West and High Plains. 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 11 |
| 50% (the "average" last frost) | May 23 |
| 10% (cautious: only 1 year in 10 freezes later) | Jun 6 |
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 3 |
| 50% (the "average" first frost) | Sep 16 |
| 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) | Jun 5 | Sep 5 |
| 32°F (freeze) | May 23 | Sep 16 |
| 28°F (hard freeze) | May 10 | 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 59435
Dates count from your average last spring frost (May 23) and first fall frost (Sep 16). 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 28–Apr 11 | May 30–Jun 13 (transplant) | – |
| Pepper (sweet and hot) | Mar 14–28 | Jun 6–20 (transplant) | – |
| Eggplant | Mar 14–28 | Jun 6–20 (transplant) | – |
| Tomatillo | Mar 28–Apr 11 | May 30–Jun 13 (transplant) | – |
| Lettuce | Mar 28–Apr 11 | May 2–23 (transplant) Apr 25–Jun 6 (sow outdoors) | Jul 22–Aug 12 (transplant) Jul 8–Aug 5 (sowing) |
| Spinach | – | Apr 11–May 2 (sow outdoors) | Jul 22–Aug 12 (sowing) |
| Kale | Mar 28–Apr 11 | Apr 25–May 9 (transplant) Apr 25–May 9 (sow outdoors) | Jun 24–Jul 22 (transplant) Jun 10–Jul 8 (sowing) |
| Collards | Mar 28–Apr 11 | Apr 25–May 23 (transplant) Apr 25–May 23 (sow outdoors) | Jun 24–Jul 22 (transplant) Jun 10–Jul 8 (sowing) |
| Broccoli | Mar 14–28 | Apr 25–May 9 (transplant) | Jun 10–Jul 8 (transplant) |
| Cabbage | Mar 14–28 | Apr 25–May 9 (transplant) | Jun 10–Jul 8 (transplant) |
| Cauliflower | Mar 14–28 | May 9–23 (transplant) | Jun 10–Jul 8 (transplant) |
| Brussels sprouts | Feb 28–Mar 14 | Apr 25–May 9 (transplant) | May 27–Jun 17 (transplant) |
| Kohlrabi | Mar 28–Apr 11 | Apr 25–May 9 (transplant) Apr 25–May 9 (sow outdoors) | Jul 8–22 (sowing) |
| Bok choy / Asian greens | – | Apr 25–May 9 (sow outdoors) | Jul 22–Aug 5 (sowing) |
| Arugula | – | Apr 25–May 23 (sow outdoors) | Jul 22–Aug 19 (sowing) |
| Mustard greens | – | Apr 25–May 16 (sow outdoors) | Jul 22–Aug 5 (sowing) |
| Swiss chard | Apr 11–25 | May 9–30 (transplant) May 9–Jun 6 (sow outdoors) | Jul 8–22 (sowing) |
| Beet | – | Apr 25–May 23 (sow outdoors) | Jul 8–22 (sowing) |
| Carrot | – | May 2–30 (sow outdoors) | Jun 24–Jul 8 (sowing) |
| Radish | – | Apr 18–May 30 (sow outdoors) | Aug 5–19 (sowing) |
| Turnip | – | Apr 25–May 16 (sow outdoors) | Jul 8–22 (sowing) |
| Parsnip | – | May 2–23 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 28–Apr 25 (sow outdoors) | Jun 24–Jul 8 (sowing) |
| Onion (bulbing) | Feb 28–Mar 14 | Apr 11–25 (transplant) | – |
| Green onion / scallion | – | Apr 11–May 9 (sow outdoors) | Jul 8–22 (sowing) |
| Leek | Feb 28–Mar 14 | Apr 25–May 9 (transplant) | – |
| Garlic | – | – | Aug 5–Sep 2 (sowing) |
| Shallot | – | Apr 11–25 (transplant) | Aug 5–Sep 2 (sowing) |
| Potato | – | Apr 25–May 9 (transplant) | May 27–Jun 10 (transplant) |
| Sweet potato | – | Jun 13–27 (transplant) | – |
| Sweet corn | – | May 30–Jun 13 (sow outdoors) | – |
| Bean, bush (snap) | – | May 30–Jun 13 (sow outdoors) | – |
| Bean, pole | – | May 30–Jun 13 (sow outdoors) | – |
| Lima bean | – | Jun 6–20 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Jun 13–Jul 4 (sow outdoors) | – |
| Cucumber | Apr 25–May 2 | May 30–Jun 13 (transplant) May 30–Jun 13 (sow outdoors) | – |
| Summer squash / zucchini | Apr 25–May 2 | May 30–Jun 13 (transplant) May 30–Jun 13 (sow outdoors) | – |
| Winter squash | Apr 25–May 2 | May 30–Jun 13 (transplant) May 30–Jun 13 (sow outdoors) | – |
| Pumpkin | – | May 30–Jun 13 (sow outdoors) | – |
| Watermelon | Apr 25–May 2 | Jun 6–20 (transplant) Jun 6–20 (sow outdoors) | – |
| Cantaloupe / muskmelon | Apr 25–May 2 | Jun 6–20 (transplant) Jun 6–20 (sow outdoors) | – |
| Okra | Apr 11–25 | Jun 6–20 (transplant) Jun 6–20 (sow outdoors) | – |
| Celery | Feb 28–Mar 14 | May 30–Jun 6 (transplant) | – |
| Basil | Apr 11–25 | May 30–Jun 13 (transplant) May 30–Jun 13 (sow outdoors) | – |
| Cilantro | – | May 9–Jun 6 (sow outdoors) | Jul 22–Aug 5 (sowing) |
| Parsley | Mar 14–28 | May 9–23 (transplant) May 2–23 (sow outdoors) | – |
| Dill | – | May 23–Jun 6 (sow outdoors) | Jul 22–Aug 5 (sowing) |
| Sunflower | – | May 23–Jun 6 (sow outdoors) | – |
| Asparagus (crowns) | – | Apr 25–May 9 (transplant) | – |
| Rhubarb (crowns) | – | Apr 25–May 9 (transplant) | – |
| Strawberry (plants) | – | Apr 25–May 9 (transplant) | Jul 8–Aug 5 (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: Shelby, MT (NOAA GHCN-Daily ID USC00247500), elevation 3,325 ft, 9.5 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Cut Bank Muni AP, MT | 15 mi | May 24 | Sep 15 |
| Valier, MT | 21 mi | May 17 | Sep 24 |
| Sunburst 8 E, MT | 26 mi | May 17 | Sep 25 |
The average last-frost dates of these stations span 7 days, a rough guide to local variation. See data sources & methods.
Frost questions for 59435
When is the last frost in 59435?
The average (50% chance) last spring freeze of 32°F for ZIP 59435 is May 23. For a more cautious planting date, use June 6, when only 1 year in 10 still sees a later freeze.
When is the first frost in 59435?
The average first fall freeze is September 16. In 1 year in 10 it comes by September 3.
What hardiness zone is 59435?
ZIP 59435 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 59435 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
59454 Kevin 59466 59474 Shelby 59482 Sunburst 59486 Valier 59425 Conrad 59444 Eagle Creek Colony 59427 Santa Rita
Other ZIP codes in Toole County
59444 59454 59466 59474 59482 59484 All Toole County frost dates · Montana 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.