Fall in zone 6aPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 59866 (St. Regis, 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, Superior, MT (15 miles away).
- Average last spring frostMay 1750% 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)125 daysmedian, 32°F threshold
- USDA hardiness zone6a-10 to -5°F avg. coldest night
Get The Dial for 59866 (St. Regis)
Frost and freeze alerts from the NWS forecast for 59866, the spring soil-temperature heads-up for pre-emergent, and a short weekly yard-timing email.
- Freeze alerts
- Soil-temp heads-up
- Weekly yard to-dos
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.
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
No soil station with a fresh reading within 62 miles.
4-inch depth
No soil station with a fresh reading within 62 miles.
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 59866 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
No soil reading near this ZIP. Typical extension timing for your region: spring 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 1 |
| 50% (the "average" last frost) | May 17 |
| 10% (cautious: only 1 year in 10 freezes later) | Jun 8 |
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 6 |
| 50% (the "average" first frost) | Sep 23 |
| 90% (late: most years have frozen by now) | Oct 7 |
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 9 |
| 32°F (freeze) | May 17 | Sep 23 |
| 28°F (hard freeze) | May 1 | Oct 6 |
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 59866
Dates count from your average last spring frost (May 17) 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 22–Apr 5 | May 24–Jun 7 (transplant) | – |
| Pepper (sweet and hot) | Mar 8–22 | May 31–Jun 14 (transplant) | – |
| Eggplant | Mar 8–22 | May 31–Jun 14 (transplant) | – |
| Tomatillo | Mar 22–Apr 5 | May 24–Jun 7 (transplant) | – |
| Lettuce | Mar 22–Apr 5 | Apr 26–May 17 (transplant) Apr 19–May 31 (sow outdoors) | Jul 29–Aug 19 (transplant) Jul 15–Aug 12 (sowing) |
| Spinach | – | Apr 5–26 (sow outdoors) | Jul 29–Aug 19 (sowing) |
| Kale | Mar 22–Apr 5 | Apr 19–May 3 (transplant) Apr 19–May 3 (sow outdoors) | Jul 1–29 (transplant) Jun 17–Jul 15 (sowing) |
| Collards | Mar 22–Apr 5 | Apr 19–May 17 (transplant) Apr 19–May 17 (sow outdoors) | Jul 1–29 (transplant) Jun 17–Jul 15 (sowing) |
| Broccoli | Mar 8–22 | Apr 19–May 3 (transplant) | Jun 17–Jul 15 (transplant) |
| Cabbage | Mar 8–22 | Apr 19–May 3 (transplant) | Jun 17–Jul 15 (transplant) |
| Cauliflower | Mar 8–22 | May 3–17 (transplant) | Jun 17–Jul 15 (transplant) |
| Brussels sprouts | Feb 22–Mar 8 | Apr 19–May 3 (transplant) | Jun 3–24 (transplant) |
| Kohlrabi | Mar 22–Apr 5 | Apr 19–May 3 (transplant) Apr 19–May 3 (sow outdoors) | Jul 15–29 (sowing) |
| Bok choy / Asian greens | – | Apr 19–May 3 (sow outdoors) | Jul 29–Aug 12 (sowing) |
| Arugula | – | Apr 19–May 17 (sow outdoors) | Jul 29–Aug 26 (sowing) |
| Mustard greens | – | Apr 19–May 10 (sow outdoors) | Jul 29–Aug 12 (sowing) |
| Swiss chard | Apr 5–19 | May 3–24 (transplant) May 3–31 (sow outdoors) | Jul 15–29 (sowing) |
| Beet | – | Apr 19–May 17 (sow outdoors) | Jul 15–29 (sowing) |
| Carrot | – | Apr 26–May 24 (sow outdoors) | Jul 1–15 (sowing) |
| Radish | – | Apr 12–May 24 (sow outdoors) | Aug 12–26 (sowing) |
| Turnip | – | Apr 19–May 10 (sow outdoors) | Jul 15–29 (sowing) |
| Parsnip | – | Apr 26–May 17 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 22–Apr 19 (sow outdoors) | Jul 1–15 (sowing) |
| Onion (bulbing) | Feb 22–Mar 8 | Apr 5–19 (transplant) | – |
| Green onion / scallion | – | Apr 5–May 3 (sow outdoors) | Jul 15–29 (sowing) |
| Leek | Feb 22–Mar 8 | Apr 19–May 3 (transplant) | – |
| Garlic | – | – | Aug 12–Sep 9 (sowing) |
| Shallot | – | Apr 5–19 (transplant) | Aug 12–Sep 9 (sowing) |
| Potato | – | Apr 19–May 3 (transplant) | Jun 3–17 (transplant) |
| Sweet potato | – | Jun 7–21 (transplant) | – |
| Sweet corn | – | May 24–Jun 7 (sow outdoors) | – |
| Bean, bush (snap) | – | May 24–Jun 7 (sow outdoors) | – |
| Bean, pole | – | May 24–Jun 7 (sow outdoors) | – |
| Lima bean | – | May 31–Jun 14 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Jun 7–28 (sow outdoors) | – |
| Cucumber | Apr 19–26 | May 24–Jun 7 (transplant) May 24–Jun 7 (sow outdoors) | – |
| Summer squash / zucchini | Apr 19–26 | May 24–Jun 7 (transplant) May 24–Jun 7 (sow outdoors) | – |
| Winter squash | Apr 19–26 | May 24–Jun 7 (transplant) May 24–Jun 7 (sow outdoors) | – |
| Pumpkin | – | May 24–Jun 7 (sow outdoors) | – |
| Watermelon | Apr 19–26 | May 31–Jun 14 (transplant) May 31–Jun 14 (sow outdoors) | – |
| Cantaloupe / muskmelon | Apr 19–26 | May 31–Jun 14 (transplant) May 31–Jun 14 (sow outdoors) | – |
| Okra | Apr 5–19 | May 31–Jun 14 (transplant) May 31–Jun 14 (sow outdoors) | – |
| Celery | Feb 22–Mar 8 | May 24–31 (transplant) | – |
| Basil | Apr 5–19 | May 24–Jun 7 (transplant) May 24–Jun 7 (sow outdoors) | – |
| Cilantro | – | May 3–31 (sow outdoors) | Jul 29–Aug 12 (sowing) |
| Parsley | Mar 8–22 | May 3–17 (transplant) Apr 26–May 17 (sow outdoors) | – |
| Dill | – | May 17–31 (sow outdoors) | Jul 29–Aug 12 (sowing) |
| Sunflower | – | May 17–31 (sow outdoors) | – |
| Asparagus (crowns) | – | Apr 19–May 3 (transplant) | – |
| Rhubarb (crowns) | – | Apr 19–May 3 (transplant) | – |
| Strawberry (plants) | – | Apr 19–May 3 (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: Superior, MT (NOAA GHCN-Daily ID USW00024159), elevation 2,710 ft, 15.0 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Thompson Falls Ph, MT | 21 mi | May 7 | Oct 4 |
| Mullan Pass Vor/dme, ID | 26 mi | Jun 10 | Sep 23 |
| Mullan, ID | 33 mi | May 12 | Sep 30 |
The average last-frost dates of these stations span 34 days, a rough guide to local variation. See data sources & methods.
Frost questions for 59866
When is the last frost in 59866?
The average (50% chance) last spring freeze of 32°F for ZIP 59866 is May 17. For a more cautious planting date, use June 8, when only 1 year in 10 still sees a later freeze.
When is the first frost in 59866?
The average first fall freeze is September 23. In 1 year in 10 it comes by September 6.
What hardiness zone is 59866?
ZIP 59866 is in USDA zone 6a (-10 to -5°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 59866 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
59842 Haugan 59830 De Borgia 59856 Paradise 59872 Riverbend 59859 Weeksville 59867 Saltese 59873 Belknap 83802
Other ZIP codes in Mineral County
59820 59830 59842 59867 59872 All Mineral County frost dates · Montana frost dates
Never miss a frost: get The Dial
Weekly yard timing, plus frost and soil-temperature alerts for your ZIP code.
- Freeze alerts
- Soil-temp heads-up
- Weekly yard to-dos
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.