Fall in zone 4aPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 59433 (Dutton, 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, Choteau 8NE, MT (15 miles away).
- Average last spring frostMay 2050% chance of a 32°F freeze after this date
- Average first fall frostSep 2250% chance of a 32°F freeze by this date
- Growing season (frost-free)123 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 (31 mi), Violett (45 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 (31 mi), Violett (45 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 59433 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 7 |
| 50% (the "average" last frost) | May 20 |
| 10% (cautious: only 1 year in 10 freezes later) | Jun 4 |
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 8 |
| 50% (the "average" first frost) | Sep 22 |
| 90% (late: most years have frozen by now) | Oct 4 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | Jun 7 | Sep 9 |
| 32°F (freeze) | May 20 | Sep 22 |
| 28°F (hard freeze) | May 8 | Oct 1 |
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 59433
Dates count from your average last spring frost (May 20) and first fall frost (Sep 22). 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 25–Apr 8 | May 27–Jun 10 (transplant) | – |
| Pepper (sweet and hot) | Mar 11–25 | Jun 3–17 (transplant) | – |
| Eggplant | Mar 11–25 | Jun 3–17 (transplant) | – |
| Tomatillo | Mar 25–Apr 8 | May 27–Jun 10 (transplant) | – |
| Lettuce | Mar 25–Apr 8 | Apr 29–May 20 (transplant) Apr 22–Jun 3 (sow outdoors) | Jul 28–Aug 18 (transplant) Jul 14–Aug 11 (sowing) |
| Spinach | – | Apr 8–29 (sow outdoors) | Jul 28–Aug 18 (sowing) |
| Kale | Mar 25–Apr 8 | Apr 22–May 6 (transplant) Apr 22–May 6 (sow outdoors) | Jun 30–Jul 28 (transplant) Jun 16–Jul 14 (sowing) |
| Collards | Mar 25–Apr 8 | Apr 22–May 20 (transplant) Apr 22–May 20 (sow outdoors) | Jun 30–Jul 28 (transplant) Jun 16–Jul 14 (sowing) |
| Broccoli | Mar 11–25 | Apr 22–May 6 (transplant) | Jun 16–Jul 14 (transplant) |
| Cabbage | Mar 11–25 | Apr 22–May 6 (transplant) | Jun 16–Jul 14 (transplant) |
| Cauliflower | Mar 11–25 | May 6–20 (transplant) | Jun 16–Jul 14 (transplant) |
| Brussels sprouts | Feb 25–Mar 11 | Apr 22–May 6 (transplant) | Jun 2–23 (transplant) |
| Kohlrabi | Mar 25–Apr 8 | Apr 22–May 6 (transplant) Apr 22–May 6 (sow outdoors) | Jul 14–28 (sowing) |
| Bok choy / Asian greens | – | Apr 22–May 6 (sow outdoors) | Jul 28–Aug 11 (sowing) |
| Arugula | – | Apr 22–May 20 (sow outdoors) | Jul 28–Aug 25 (sowing) |
| Mustard greens | – | Apr 22–May 13 (sow outdoors) | Jul 28–Aug 11 (sowing) |
| Swiss chard | Apr 8–22 | May 6–27 (transplant) May 6–Jun 3 (sow outdoors) | Jul 14–28 (sowing) |
| Beet | – | Apr 22–May 20 (sow outdoors) | Jul 14–28 (sowing) |
| Carrot | – | Apr 29–May 27 (sow outdoors) | Jun 30–Jul 14 (sowing) |
| Radish | – | Apr 15–May 27 (sow outdoors) | Aug 11–25 (sowing) |
| Turnip | – | Apr 22–May 13 (sow outdoors) | Jul 14–28 (sowing) |
| Parsnip | – | Apr 29–May 20 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 25–Apr 22 (sow outdoors) | Jun 30–Jul 14 (sowing) |
| Onion (bulbing) | Feb 25–Mar 11 | Apr 8–22 (transplant) | – |
| Green onion / scallion | – | Apr 8–May 6 (sow outdoors) | Jul 14–28 (sowing) |
| Leek | Feb 25–Mar 11 | Apr 22–May 6 (transplant) | – |
| Garlic | – | – | Aug 11–Sep 8 (sowing) |
| Shallot | – | Apr 8–22 (transplant) | Aug 11–Sep 8 (sowing) |
| Potato | – | Apr 22–May 6 (transplant) | Jun 2–16 (transplant) |
| Sweet potato | – | Jun 10–24 (transplant) | – |
| Sweet corn | – | May 27–Jun 10 (sow outdoors) | – |
| Bean, bush (snap) | – | May 27–Jun 10 (sow outdoors) | – |
| Bean, pole | – | May 27–Jun 10 (sow outdoors) | – |
| Lima bean | – | Jun 3–17 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Jun 10–Jul 1 (sow outdoors) | – |
| Cucumber | Apr 22–29 | May 27–Jun 10 (transplant) May 27–Jun 10 (sow outdoors) | – |
| Summer squash / zucchini | Apr 22–29 | May 27–Jun 10 (transplant) May 27–Jun 10 (sow outdoors) | – |
| Winter squash | Apr 22–29 | May 27–Jun 10 (transplant) May 27–Jun 10 (sow outdoors) | – |
| Pumpkin | – | May 27–Jun 10 (sow outdoors) | – |
| Watermelon | Apr 22–29 | Jun 3–17 (transplant) Jun 3–17 (sow outdoors) | – |
| Cantaloupe / muskmelon | Apr 22–29 | Jun 3–17 (transplant) Jun 3–17 (sow outdoors) | – |
| Okra | Apr 8–22 | Jun 3–17 (transplant) Jun 3–17 (sow outdoors) | – |
| Celery | Feb 25–Mar 11 | May 27–Jun 3 (transplant) | – |
| Basil | Apr 8–22 | May 27–Jun 10 (transplant) May 27–Jun 10 (sow outdoors) | – |
| Cilantro | – | May 6–Jun 3 (sow outdoors) | Jul 28–Aug 11 (sowing) |
| Parsley | Mar 11–25 | May 6–20 (transplant) Apr 29–May 20 (sow outdoors) | – |
| Dill | – | May 20–Jun 3 (sow outdoors) | Jul 28–Aug 11 (sowing) |
| Sunflower | – | May 20–Jun 3 (sow outdoors) | – |
| Asparagus (crowns) | – | Apr 22–May 6 (transplant) | – |
| Rhubarb (crowns) | – | Apr 22–May 6 (transplant) | – |
| Strawberry (plants) | – | Apr 22–May 6 (transplant) | Jul 14–Aug 11 (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: Choteau 8NE, MT (NOAA GHCN-Daily ID USC00241738), elevation 3,741 ft, 15.3 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Carter 14 W, MT | 23 mi | May 23 | Sep 23 |
| Fairfield, MT | 23 mi | May 13 | Sep 27 |
| Conrad, MT | 23 mi | May 20 | Sep 19 |
The average last-frost dates of these stations span 10 days, a rough guide to local variation. See data sources & methods.
Frost questions for 59433
When is the last frost in 59433?
The average (50% chance) last spring freeze of 32°F for ZIP 59433 is May 20. For a more cautious planting date, use June 4, when only 1 year in 10 still sees a later freeze.
When is the first frost in 59433?
The average first fall freeze is September 22. In 1 year in 10 it comes by September 8.
What hardiness zone is 59433?
ZIP 59433 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 59433 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
59468 Power 59416 Brady 59487 Vaughn 59443 Fort Shaw 59425 Conrad 59404 Sun Prairie 59436 Fairfield 59440 Floweree
Other ZIP codes in Teton County
59419 59422 59436 59467 59468 All Teton 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.