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Frost dates for ZIP 59322 (Garfield County, 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, Cohagen, MT (3 miles away).

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

45°F Below 50°F
24-hour average · latest 45°F, as of Oct 18, 1:00 AM CDT

30°50°55°70°90°

Estimate Not a measurement at this ZIP: distance-weighted average of Jordan (39 mi).

4-inch depth

46°F Below 50°F
24-hour average · latest 47°F, as of Oct 18, 1:00 AM CDT

30°50°55°70°90°

Estimate Not a measurement at this ZIP: distance-weighted average of Jordan (39 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 59322 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.

JanFebMarAprMayJunJulAugSepOctNovDecLight blue: spring freeze risk (90% to 10%). Tan: fall freeze risk (10% to 90%). Dark lines: 50% dates.

Last spring frost odds

Chance of a 32°F freeze after this dateDate
90% (early: most years still freeze after this)May 12
50% (the "average" last frost)May 25
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 dateDate
10% (early: 1 year in 10 freezes this soon)Aug 31
50% (the "average" first frost)Sep 14
90% (late: most years have frozen by now)Sep 26

Light frost, freeze and hard freeze

ThresholdLast spring (50%)First fall (50%)
36°F (light frost possible on clear, calm nights)Jun 6Sep 4
32°F (freeze)May 25Sep 14
28°F (hard freeze)May 16Sep 23

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 59322

Dates count from your average last spring frost (May 25) and first fall frost (Sep 14). Half of years have a frost after the spring date, so give tender crops (tomatoes, peppers, squash) some slack.

Start seeds indoorsSpring plantingFall plantingLast frostFirst frostJanFebMarAprMayJunJulAugSepOctNovDecTomatoPepperEggplantTomatilloLettuceSpinachKaleCollardsBroccoliCabbageCauliflowerBrussels sproutsKohlrabiBok choy / Asian greensArugulaMustard greensSwiss chardBeetCarrotRadishTurnipParsnipPeaOnionGreen onion / scallionLeekGarlicShallotPotatoSweet potatoSweet cornBean, bushBean, poleLima beanSouthern peaCucumberSummer squash / zucchiniWinter squashPumpkinWatermelonCantaloupe / muskmelonOkraCeleryBasilCilantroParsleyDillSunflowerAsparagusRhubarbStrawberry
CropStart indoorsSpring plantingFall planting
TomatoMar 30–Apr 13Jun 1–15 (transplant)–
Pepper (sweet and hot)Mar 16–30Jun 8–22 (transplant)–
EggplantMar 16–30Jun 8–22 (transplant)–
TomatilloMar 30–Apr 13Jun 1–15 (transplant)–
LettuceMar 30–Apr 13May 4–25 (transplant)
Apr 27–Jun 8 (sow outdoors)
Jul 20–Aug 10 (transplant)
Jul 6–Aug 3 (sowing)
Spinach–Apr 13–May 4 (sow outdoors)Jul 20–Aug 10 (sowing)
KaleMar 30–Apr 13Apr 27–May 11 (transplant)
Apr 27–May 11 (sow outdoors)
Jun 22–Jul 20 (transplant)
Jun 8–Jul 6 (sowing)
CollardsMar 30–Apr 13Apr 27–May 25 (transplant)
Apr 27–May 25 (sow outdoors)
Jun 22–Jul 20 (transplant)
Jun 8–Jul 6 (sowing)
BroccoliMar 16–30Apr 27–May 11 (transplant)Jun 8–Jul 6 (transplant)
CabbageMar 16–30Apr 27–May 11 (transplant)Jun 8–Jul 6 (transplant)
CauliflowerMar 16–30May 11–25 (transplant)Jun 8–Jul 6 (transplant)
Brussels sproutsMar 2–16Apr 27–May 11 (transplant)May 25–Jun 15 (transplant)
KohlrabiMar 30–Apr 13Apr 27–May 11 (transplant)
Apr 27–May 11 (sow outdoors)
Jul 6–20 (sowing)
Bok choy / Asian greens–Apr 27–May 11 (sow outdoors)Jul 20–Aug 3 (sowing)
Arugula–Apr 27–May 25 (sow outdoors)Jul 20–Aug 17 (sowing)
Mustard greens–Apr 27–May 18 (sow outdoors)Jul 20–Aug 3 (sowing)
Swiss chardApr 13–27May 11–Jun 1 (transplant)
May 11–Jun 8 (sow outdoors)
Jul 6–20 (sowing)
Beet–Apr 27–May 25 (sow outdoors)Jul 6–20 (sowing)
Carrot–May 4–Jun 1 (sow outdoors)Jun 22–Jul 6 (sowing)
Radish–Apr 20–Jun 1 (sow outdoors)Aug 3–17 (sowing)
Turnip–Apr 27–May 18 (sow outdoors)Jul 6–20 (sowing)
Parsnip–May 4–25 (sow outdoors)–
Pea (garden, snap, snow)–Mar 30–Apr 27 (sow outdoors)Jun 22–Jul 6 (sowing)
Onion (bulbing)Mar 2–16Apr 13–27 (transplant)–
Green onion / scallion–Apr 13–May 11 (sow outdoors)Jul 6–20 (sowing)
LeekMar 2–16Apr 27–May 11 (transplant)–
Garlic––Aug 3–31 (sowing)
Shallot–Apr 13–27 (transplant)Aug 3–31 (sowing)
Potato–Apr 27–May 11 (transplant)May 25–Jun 8 (transplant)
Sweet potato–Jun 15–29 (transplant)–
Sweet corn–Jun 1–15 (sow outdoors)–
Bean, bush (snap)–Jun 1–15 (sow outdoors)–
Bean, pole–Jun 1–15 (sow outdoors)–
Lima bean–Jun 8–22 (sow outdoors)–
Southern pea (cowpea, black-eyed pea)–Jun 15–Jul 6 (sow outdoors)–
CucumberApr 27–May 4Jun 1–15 (transplant)
Jun 1–15 (sow outdoors)
–
Summer squash / zucchiniApr 27–May 4Jun 1–15 (transplant)
Jun 1–15 (sow outdoors)
–
Winter squashApr 27–May 4Jun 1–15 (transplant)
Jun 1–15 (sow outdoors)
–
Pumpkin–Jun 1–15 (sow outdoors)–
WatermelonApr 27–May 4Jun 8–22 (transplant)
Jun 8–22 (sow outdoors)
–
Cantaloupe / muskmelonApr 27–May 4Jun 8–22 (transplant)
Jun 8–22 (sow outdoors)
–
OkraApr 13–27Jun 8–22 (transplant)
Jun 8–22 (sow outdoors)
–
CeleryMar 2–16Jun 1–8 (transplant)–
BasilApr 13–27Jun 1–15 (transplant)
Jun 1–15 (sow outdoors)
–
Cilantro–May 11–Jun 8 (sow outdoors)Jul 20–Aug 3 (sowing)
ParsleyMar 16–30May 11–25 (transplant)
May 4–25 (sow outdoors)
–
Dill–May 25–Jun 8 (sow outdoors)Jul 20–Aug 3 (sowing)
Sunflower–May 25–Jun 8 (sow outdoors)–
Asparagus (crowns)–Apr 27–May 11 (transplant)–
Rhubarb (crowns)–Apr 27–May 11 (transplant)–
Strawberry (plants)–Apr 27–May 11 (transplant)Jul 6–Aug 3 (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: Cohagen, MT (NOAA GHCN-Daily ID USC00241875), elevation 2,720 ft, 3.4 miles from the ZIP's center point. NOAA completeness flag: S (standard, 24+ years).

Nearby stations

StationDistanceLast frost (50%)First frost (50%)
Jordan, MT21 miMay 21Sep 18
Jordan AP, MT23 miMay 18Sep 20
Rock Springs, MT26 miMay 15Sep 25

The average last-frost dates of these stations span 10 days, a rough guide to local variation. See data sources & methods.

Frost questions for 59322

When is the last frost in 59322?

The average (50% chance) last spring freeze of 32°F for ZIP 59322 is May 25. 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 59322?

The average first fall freeze is September 14. In 1 year in 10 it comes by August 31.

What hardiness zone is 59322?

ZIP 59322 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 59322 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

59312 59337 Jordan 59214 Brockway 59039 59077 59347 Rosebud 59318 59058

Other ZIP codes in Garfield County

59058 59077 59312 59318 59337 All Garfield County frost dates · Montana frost dates