Fall in zone 4bPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 59412 (Riceville, 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, Raynesford 2 NNW, MT (6 miles away).
- Average last spring frostMay 2250% 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 zone4b-25 to -20°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
42°F Below 50°F
24-hour average · latest 42°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Lewistown 42 WSW (40 mi), Moccasin (46 mi).
4-inch depth
42°F Below 50°F
24-hour average · latest 44°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Lewistown 42 WSW (40 mi), Moccasin (46 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 59412 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 42°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 22 |
| 10% (cautious: only 1 year in 10 freezes later) | Jun 9 |
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 7 |
| 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 9 | Sep 12 |
| 32°F (freeze) | May 22 | Sep 23 |
| 28°F (hard freeze) | May 7 | Oct 2 |
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 59412
Dates count from your average last spring frost (May 22) 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 27–Apr 10 | May 29–Jun 12 (transplant) | – |
| Pepper (sweet and hot) | Mar 13–27 | Jun 5–19 (transplant) | – |
| Eggplant | Mar 13–27 | Jun 5–19 (transplant) | – |
| Tomatillo | Mar 27–Apr 10 | May 29–Jun 12 (transplant) | – |
| Lettuce | Mar 27–Apr 10 | May 1–22 (transplant) Apr 24–Jun 5 (sow outdoors) | Jul 29–Aug 19 (transplant) Jul 15–Aug 12 (sowing) |
| Spinach | – | Apr 10–May 1 (sow outdoors) | Jul 29–Aug 19 (sowing) |
| Kale | Mar 27–Apr 10 | Apr 24–May 8 (transplant) Apr 24–May 8 (sow outdoors) | Jul 1–29 (transplant) Jun 17–Jul 15 (sowing) |
| Collards | Mar 27–Apr 10 | Apr 24–May 22 (transplant) Apr 24–May 22 (sow outdoors) | Jul 1–29 (transplant) Jun 17–Jul 15 (sowing) |
| Broccoli | Mar 13–27 | Apr 24–May 8 (transplant) | Jun 17–Jul 15 (transplant) |
| Cabbage | Mar 13–27 | Apr 24–May 8 (transplant) | Jun 17–Jul 15 (transplant) |
| Cauliflower | Mar 13–27 | May 8–22 (transplant) | Jun 17–Jul 15 (transplant) |
| Brussels sprouts | Feb 27–Mar 13 | Apr 24–May 8 (transplant) | Jun 3–24 (transplant) |
| Kohlrabi | Mar 27–Apr 10 | Apr 24–May 8 (transplant) Apr 24–May 8 (sow outdoors) | Jul 15–29 (sowing) |
| Bok choy / Asian greens | – | Apr 24–May 8 (sow outdoors) | Jul 29–Aug 12 (sowing) |
| Arugula | – | Apr 24–May 22 (sow outdoors) | Jul 29–Aug 26 (sowing) |
| Mustard greens | – | Apr 24–May 15 (sow outdoors) | Jul 29–Aug 12 (sowing) |
| Swiss chard | Apr 10–24 | May 8–29 (transplant) May 8–Jun 5 (sow outdoors) | Jul 15–29 (sowing) |
| Beet | – | Apr 24–May 22 (sow outdoors) | Jul 15–29 (sowing) |
| Carrot | – | May 1–29 (sow outdoors) | Jul 1–15 (sowing) |
| Radish | – | Apr 17–May 29 (sow outdoors) | Aug 12–26 (sowing) |
| Turnip | – | Apr 24–May 15 (sow outdoors) | Jul 15–29 (sowing) |
| Parsnip | – | May 1–22 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 27–Apr 24 (sow outdoors) | Jul 1–15 (sowing) |
| Onion (bulbing) | Feb 27–Mar 13 | Apr 10–24 (transplant) | – |
| Green onion / scallion | – | Apr 10–May 8 (sow outdoors) | Jul 15–29 (sowing) |
| Leek | Feb 27–Mar 13 | Apr 24–May 8 (transplant) | – |
| Garlic | – | – | Aug 12–Sep 9 (sowing) |
| Shallot | – | Apr 10–24 (transplant) | Aug 12–Sep 9 (sowing) |
| Potato | – | Apr 24–May 8 (transplant) | Jun 3–17 (transplant) |
| Sweet potato | – | Jun 12–26 (transplant) | – |
| Sweet corn | – | May 29–Jun 12 (sow outdoors) | – |
| Bean, bush (snap) | – | May 29–Jun 12 (sow outdoors) | – |
| Bean, pole | – | May 29–Jun 12 (sow outdoors) | – |
| Lima bean | – | Jun 5–19 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Jun 12–Jul 3 (sow outdoors) | – |
| Cucumber | Apr 24–May 1 | May 29–Jun 12 (transplant) May 29–Jun 12 (sow outdoors) | – |
| Summer squash / zucchini | Apr 24–May 1 | May 29–Jun 12 (transplant) May 29–Jun 12 (sow outdoors) | – |
| Winter squash | Apr 24–May 1 | May 29–Jun 12 (transplant) May 29–Jun 12 (sow outdoors) | – |
| Pumpkin | – | May 29–Jun 12 (sow outdoors) | – |
| Watermelon | Apr 24–May 1 | Jun 5–19 (transplant) Jun 5–19 (sow outdoors) | – |
| Cantaloupe / muskmelon | Apr 24–May 1 | Jun 5–19 (transplant) Jun 5–19 (sow outdoors) | – |
| Okra | Apr 10–24 | Jun 5–19 (transplant) Jun 5–19 (sow outdoors) | – |
| Celery | Feb 27–Mar 13 | May 29–Jun 5 (transplant) | – |
| Basil | Apr 10–24 | May 29–Jun 12 (transplant) May 29–Jun 12 (sow outdoors) | – |
| Cilantro | – | May 8–Jun 5 (sow outdoors) | Jul 29–Aug 12 (sowing) |
| Parsley | Mar 13–27 | May 8–22 (transplant) May 1–22 (sow outdoors) | – |
| Dill | – | May 22–Jun 5 (sow outdoors) | Jul 29–Aug 12 (sowing) |
| Sunflower | – | May 22–Jun 5 (sow outdoors) | – |
| Asparagus (crowns) | – | Apr 24–May 8 (transplant) | – |
| Rhubarb (crowns) | – | Apr 24–May 8 (transplant) | – |
| Strawberry (plants) | – | Apr 24–May 8 (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: Raynesford 2 NNW, MT (NOAA GHCN-Daily ID USC00246902), elevation 4,215 ft, 5.5 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Neihart 8 NNW, MT | 19 mi | Jun 6 | Sep 12 |
| Shonkin 7 S, MT | 21 mi | May 24 | Sep 21 |
| Great Falls 16ST, MT | 23 mi | May 6 | Oct 1 |
The average last-frost dates of these stations span 31 days, a rough guide to local variation. See data sources & methods.
Frost questions for 59412
When is the last frost in 59412?
The average (50% chance) last spring freeze of 32°F for ZIP 59412 is May 22. For a more cautious planting date, use June 9, when only 1 year in 10 still sees a later freeze.
When is the first frost in 59412?
The average first fall freeze is September 23. In 1 year in 10 it comes by September 7.
What hardiness zone is 59412?
ZIP 59412 is in USDA zone 4b (-25 to -20°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 59412 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
59469 Raynesford 59480 Stockett 59472 Sand Coulee 59463 Monarch 59450 Highwood 59447 Geyser 59405 Malmstrom AFB 59401 Great Falls
Other ZIP codes in Cascade County
59401 59404 59405 59414 59421 59443 59463 59465 59472 59477 59480 59483 59485 59487 All Cascade County frost dates · Montana frost dates
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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.