Fall in zone 4bPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 59457 (Lewistown, 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, Lewistown Muni AP, MT (9 miles away).
- Average last spring frostMay 2350% chance of a 32°F freeze after this date
- Average first fall frostSep 2150% chance of a 32°F freeze by this date
- Growing season (frost-free)119 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
43°F Below 50°F
24-hour average · latest 43°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Moccasin (31 mi), Lewistown 42 WSW (50 mi).
4-inch depth
43°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 Moccasin (31 mi), Lewistown 42 WSW (50 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 59457 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 11 |
| 50% (the "average" last frost) | May 23 |
| 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 8 |
| 50% (the "average" first frost) | Sep 21 |
| 90% (late: most years have frozen by now) | Oct 3 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | Jun 11 | Sep 8 |
| 32°F (freeze) | May 23 | Sep 21 |
| 28°F (hard freeze) | May 9 | 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 59457
Dates count from your average last spring frost (May 23) and first fall frost (Sep 21). 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 27–Aug 17 (transplant) Jul 13–Aug 10 (sowing) |
| Spinach | – | Apr 11–May 2 (sow outdoors) | Jul 27–Aug 17 (sowing) |
| Kale | Mar 28–Apr 11 | Apr 25–May 9 (transplant) Apr 25–May 9 (sow outdoors) | Jun 29–Jul 27 (transplant) Jun 15–Jul 13 (sowing) |
| Collards | Mar 28–Apr 11 | Apr 25–May 23 (transplant) Apr 25–May 23 (sow outdoors) | Jun 29–Jul 27 (transplant) Jun 15–Jul 13 (sowing) |
| Broccoli | Mar 14–28 | Apr 25–May 9 (transplant) | Jun 15–Jul 13 (transplant) |
| Cabbage | Mar 14–28 | Apr 25–May 9 (transplant) | Jun 15–Jul 13 (transplant) |
| Cauliflower | Mar 14–28 | May 9–23 (transplant) | Jun 15–Jul 13 (transplant) |
| Brussels sprouts | Feb 28–Mar 14 | Apr 25–May 9 (transplant) | Jun 1–22 (transplant) |
| Kohlrabi | Mar 28–Apr 11 | Apr 25–May 9 (transplant) Apr 25–May 9 (sow outdoors) | Jul 13–27 (sowing) |
| Bok choy / Asian greens | – | Apr 25–May 9 (sow outdoors) | Jul 27–Aug 10 (sowing) |
| Arugula | – | Apr 25–May 23 (sow outdoors) | Jul 27–Aug 24 (sowing) |
| Mustard greens | – | Apr 25–May 16 (sow outdoors) | Jul 27–Aug 10 (sowing) |
| Swiss chard | Apr 11–25 | May 9–30 (transplant) May 9–Jun 6 (sow outdoors) | Jul 13–27 (sowing) |
| Beet | – | Apr 25–May 23 (sow outdoors) | Jul 13–27 (sowing) |
| Carrot | – | May 2–30 (sow outdoors) | Jun 29–Jul 13 (sowing) |
| Radish | – | Apr 18–May 30 (sow outdoors) | Aug 10–24 (sowing) |
| Turnip | – | Apr 25–May 16 (sow outdoors) | Jul 13–27 (sowing) |
| Parsnip | – | May 2–23 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 28–Apr 25 (sow outdoors) | Jun 29–Jul 13 (sowing) |
| Onion (bulbing) | Feb 28–Mar 14 | Apr 11–25 (transplant) | – |
| Green onion / scallion | – | Apr 11–May 9 (sow outdoors) | Jul 13–27 (sowing) |
| Leek | Feb 28–Mar 14 | Apr 25–May 9 (transplant) | – |
| Garlic | – | – | Aug 10–Sep 7 (sowing) |
| Shallot | – | Apr 11–25 (transplant) | Aug 10–Sep 7 (sowing) |
| Potato | – | Apr 25–May 9 (transplant) | Jun 1–15 (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 27–Aug 10 (sowing) |
| Parsley | Mar 14–28 | May 9–23 (transplant) May 2–23 (sow outdoors) | – |
| Dill | – | May 23–Jun 6 (sow outdoors) | Jul 27–Aug 10 (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 13–Aug 10 (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: Lewistown Muni AP, MT (NOAA GHCN-Daily ID USW00024036), elevation 4,145 ft, 9.3 miles from the ZIP's center point. NOAA completeness flag: S (standard, 24+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Lewistown, MT | 7 mi | May 14 | Sep 28 |
| Lewistown 11ESE, MT | 10 mi | May 19 | Sep 25 |
| Lewistown 11 SSE, MT | 17 mi | May 31 | Sep 14 |
The average last-frost dates of these stations span 17 days, a rough guide to local variation. See data sources & methods.
Frost questions for 59457
When is the last frost in 59457?
The average (50% chance) last spring freeze of 32°F for ZIP 59457 is May 23. 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 59457?
The average first fall freeze is September 21. In 1 year in 10 it comes by September 8.
What hardiness zone is 59457?
ZIP 59457 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 59457 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
59451 Hilger 59441 59464 Moore 59462 Moccasin 59032 Ayers Ranch Colony 59430 Denton 59471 Roy 59489 Winifred
Other ZIP codes in Fergus County
59032 59424 59430 59441 59451 59464 59471 59489 All Fergus County frost dates · Montana frost dates
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