Fall in zone 5aPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 59718 (Four Corners, 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, Bozeman 6 W EXP Farm, MT (2 miles away).
- Average last spring frostMay 2350% chance of a 32°F freeze after this date
- Average first fall frostSep 2350% chance of a 32°F freeze by this date
- Growing season (frost-free)123 daysmedian, 32°F threshold
- USDA hardiness zone5a-20 to -15°F avg. coldest night
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Frost and freeze alerts from the NWS forecast for 59718, 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
44°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 Table Mountain (23 mi).
4-inch depth
43°F Below 50°F
24-hour average · latest 46°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Table Mountain (23 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 59718 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 43°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 5 |
| 50% (the "average" last frost) | May 23 |
| 10% (cautious: only 1 year in 10 freezes later) | Jun 12 |
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 4 |
| 50% (the "average" first frost) | Sep 23 |
| 90% (late: most years have frozen by now) | Oct 6 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | Jun 13 | Sep 9 |
| 32°F (freeze) | May 23 | Sep 23 |
| 28°F (hard freeze) | May 2 | Oct 3 |
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 59718
Dates count from your average last spring frost (May 23) and first fall frost (Sep 23). 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 29–Aug 19 (transplant) Jul 15–Aug 12 (sowing) |
| Spinach | – | Apr 11–May 2 (sow outdoors) | Jul 29–Aug 19 (sowing) |
| Kale | Mar 28–Apr 11 | Apr 25–May 9 (transplant) Apr 25–May 9 (sow outdoors) | Jul 1–29 (transplant) Jun 17–Jul 15 (sowing) |
| Collards | Mar 28–Apr 11 | Apr 25–May 23 (transplant) Apr 25–May 23 (sow outdoors) | Jul 1–29 (transplant) Jun 17–Jul 15 (sowing) |
| Broccoli | Mar 14–28 | Apr 25–May 9 (transplant) | Jun 17–Jul 15 (transplant) |
| Cabbage | Mar 14–28 | Apr 25–May 9 (transplant) | Jun 17–Jul 15 (transplant) |
| Cauliflower | Mar 14–28 | May 9–23 (transplant) | Jun 17–Jul 15 (transplant) |
| Brussels sprouts | Feb 28–Mar 14 | Apr 25–May 9 (transplant) | Jun 3–24 (transplant) |
| Kohlrabi | Mar 28–Apr 11 | Apr 25–May 9 (transplant) Apr 25–May 9 (sow outdoors) | Jul 15–29 (sowing) |
| Bok choy / Asian greens | – | Apr 25–May 9 (sow outdoors) | Jul 29–Aug 12 (sowing) |
| Arugula | – | Apr 25–May 23 (sow outdoors) | Jul 29–Aug 26 (sowing) |
| Mustard greens | – | Apr 25–May 16 (sow outdoors) | Jul 29–Aug 12 (sowing) |
| Swiss chard | Apr 11–25 | May 9–30 (transplant) May 9–Jun 6 (sow outdoors) | Jul 15–29 (sowing) |
| Beet | – | Apr 25–May 23 (sow outdoors) | Jul 15–29 (sowing) |
| Carrot | – | May 2–30 (sow outdoors) | Jul 1–15 (sowing) |
| Radish | – | Apr 18–May 30 (sow outdoors) | Aug 12–26 (sowing) |
| Turnip | – | Apr 25–May 16 (sow outdoors) | Jul 15–29 (sowing) |
| Parsnip | – | May 2–23 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 28–Apr 25 (sow outdoors) | Jul 1–15 (sowing) |
| Onion (bulbing) | Feb 28–Mar 14 | Apr 11–25 (transplant) | – |
| Green onion / scallion | – | Apr 11–May 9 (sow outdoors) | Jul 15–29 (sowing) |
| Leek | Feb 28–Mar 14 | Apr 25–May 9 (transplant) | – |
| Garlic | – | – | Aug 12–Sep 9 (sowing) |
| Shallot | – | Apr 11–25 (transplant) | Aug 12–Sep 9 (sowing) |
| Potato | – | Apr 25–May 9 (transplant) | Jun 3–17 (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 29–Aug 12 (sowing) |
| Parsley | Mar 14–28 | May 9–23 (transplant) May 2–23 (sow outdoors) | – |
| Dill | – | May 23–Jun 6 (sow outdoors) | Jul 29–Aug 12 (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 15–Aug 12 (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: Bozeman 6 W EXP Farm, MT (NOAA GHCN-Daily ID USC00241047), elevation 4,775 ft, 2.4 miles from the ZIP's center point. NOAA completeness flag: S (standard, 24+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Bozeman Montana State Univ, MT | 6 mi | May 26 | Sep 22 |
| Bozeman Gallatin Fld, MT | 10 mi | May 26 | Sep 16 |
| Logan Landfill, MT | 20 mi | May 26 | Sep 15 |
The average last-frost dates of these stations span 3 days, a rough guide to local variation. See data sources & methods.
Frost questions for 59718
When is the last frost in 59718?
The average (50% chance) last spring freeze of 32°F for ZIP 59718 is May 23. For a more cautious planting date, use June 12, when only 1 year in 10 still sees a later freeze.
When is the first frost in 59718?
The average first fall freeze is September 23. In 1 year in 10 it comes by September 4.
What hardiness zone is 59718?
ZIP 59718 is in USDA zone 5a (-20 to -15°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 59718 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
59741 Gallatin River Ranch 59715 Bozeman 59745 Norris 59760 Willow Creek 59714 Belgrade 59752 Wheatland 59716 Big Sky 59027 South Glastonbury
Other ZIP codes in Gallatin County
59714 59715 59730 59741 59752 59758 59760 All Gallatin 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.