Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated

Planting zone for 59085 — Two Dot, MT

ZIP code 59085 (Two Dot, Wheatland County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is June 3 and the first fall frost September 8.

Where ZIP 59085 is

Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone4b−25 to −20 °F
Coldest night−31.7 to −28.9 °C
Last frostJun 3
First frostSep 8
2012 zone4a

Was 4a on the 2012 map — half a zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 4b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Two Dot, MT…

Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates in Two Dot, MT

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostJune 3median — 50% chance of a later frost
Safe for tender plantsJune 25only 10% chance of frost after
First fall frostSeptember 8median — 10% chance by Aug 23
Growing season94 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 18 and returns around September 23.

From the NOAA station Martinsdale 3 Nnw, MT — 14 miles away, elevation 4,800 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in 59085

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 22 – May 6
SpinachSow outdoors · Apr 22 – May 13
Broccoli, cabbageStart indoors · Mar 25 – Apr 8
Broccoli, cabbageTransplant · May 13 – May 27
Onion setsPlant outdoors · May 6 – May 20
PotatoesPlant outdoors · May 13 – May 27
LettuceSow outdoors · May 6 – May 20
Carrots, beetsSow outdoors · May 13 – May 27
TomatoesStart indoors · Apr 8 – Apr 22
TomatoesTransplant · Jun 10 – Jun 24
Peppers, eggplantStart indoors · Mar 25 – Apr 8
Peppers, eggplantTransplant · Jun 17 – Jul 1
BeansSow outdoors · Jun 10 – Jun 24
Sweet cornSow outdoors · Jun 10 – Jun 24
Cucumbers, squashSow outdoors · Jun 10 – Jun 24
Fall lettuce, spinachSow outdoors · Jul 14 – Jul 28
GarlicPlant cloves · Aug 25 – Sep 29
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jun 3) and first fall frost (Sep 8) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 59085 came on Mar 31 — 29 days earlier than the 1991–2020 average (Apr 29).

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Native plants for zone 4b in Montana

506 plants native to the lower 48 states, recorded in Montana, and rated by the USDA to survive −25 °F or colder — the bottom of zone 4b. Each links to its USDA PLANTS profile.

Trees 23

American elm120 ft · blooms early spring · medium shade tolerance · to −46 °Fbalsam poplar80 ft · blooms late spring · high shade tolerance · to −79 °Fblack locust60 ft · blooms spring · high shade tolerance · to −37 °Fboxelder60 ft · blooms early spring · low shade tolerance · to −46 °FDouglas-fir200 ft · blooms mid spring · medium shade tolerance · to −33 °Feastern cottonwood190 ft · blooms spring · high shade tolerance · to −43 °F

Shrubs 87

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °Falderleaf mountain mahogany15 ft · blooms late spring · medium shade tolerance · to −41 °Falpine laurel1 ft · blooms late spring · low shade tolerance · to −28 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican plum24 ft · blooms mid spring · high shade tolerance · to −38 °Fantelope bitterbrush6 ft · blooms early spring · medium shade tolerance · to −36 °F

Wildflowers & perennials 229

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °Falpine mountainsorrel1 ft · blooms mid summer · medium shade tolerance · to −43 °Falpine sweetvetch2 ft · blooms early summer · high shade tolerance · to −62 °FAmerican alpine speedwell1 ft · blooms summer · medium shade tolerance · to −28 °FAmerican bistort1.5 ft · blooms mid spring · high shade tolerance · to −38 °F

Grasses 155

Alaska oniongrass3 ft · blooms mid spring · low shade tolerance · to −33 °Falkali cordgrass3 ft · blooms late summer · high shade tolerance · to −38 °Falkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °FAlpine Meadow-Foxtail0.5 ft · blooms mid spring · medium shade tolerance · to −33 °Falpine timothy1.4 ft · blooms late spring · medium shade tolerance · to −43 °Fanalogue sedge1.5 ft · blooms late spring · medium shade tolerance · to −38 °F

Vines 3

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Fwestern white clematis1 ft · blooms mid summer · medium shade tolerance · to −38 °F

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in Two Dot, MT.

Soil in Two Dot, MT

The soil mapped at the center of ZIP 59085 is Cabba — loam, well drained.

TextureLoama good balance for most vegetables
pH8.1alkaline; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2%moderate
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Cabba-Rock outcrop complex, cool, 15 to 60 percent slopes.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 59085; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Two Dot, MT

Summer high83 °Faverage high, August
Winter low15 °Faverage low, February
Hot days11days a year at 90 °F or more
Freezing nights195nights a year at 32 °F or less
Growing degree days1,486base 50 °F — the season’s usable heat
Longest day15 h 48 mindaylight on June 21
Shortest day8 h 36 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation13.5 inper year, rain and melted snow
Snowfall43 inper year

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 37 °F, low 16 °F 37°16° JanFebruary: average high 39 °F, low 15 °F 39°15° FebMarch: average high 47 °F, low 22 °F 47°22° MarApril: average high 56 °F, low 28 °F 56°28° AprMay: average high 65 °F, low 35 °F 65°35° MayJune: average high 73 °F, low 43 °F 73°43° JunJuly: average high 82 °F, low 47 °F 82°47° JulAugust: average high 83 °F, low 45 °F 83°45° AugSeptember: average high 72 °F, low 38 °F 72°38° SepOctober: average high 58 °F, low 30 °F 58°30° OctNovember: average high 44 °F, low 22 °F 44°22° NovDecember: average high 36 °F, low 16 °F 36°16° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″January: 0.49 in precipitation, 7.4 in snowfall 0.5❄7 JanFebruary: 0.34 in precipitation, 4.4 in snowfall 0.3❄4 FebMarch: 0.57 in precipitation, 7.8 in snowfall 0.6❄8 MarApril: 1.34 in precipitation, 6.6 in snowfall 1.3❄7 AprMay: 2.58 in precipitation, 1.3 in snowfall 2.6❄1 MayJune: 2.59 in precipitation 2.6 JunJuly: 1.39 in precipitation 1.4 JulAugust: 1.16 in precipitation, 0.1 in snowfall 1.2 AugSeptember: 0.97 in precipitation, 0.5 in snowfall 1.0❄1 SepOctober: 0.77 in precipitation, 3.2 in snowfall 0.8❄3 OctNovember: 0.78 in precipitation, 6 in snowfall 0.8❄6 NovDecember: 0.55 in precipitation, 6.1 in snowfall 0.6❄6 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Martinsdale 3 Nnw, MT (14 mi away); precipitation: Martinsdale 3 Nnw, MT (14 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

2 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

590534b
Martinsdale, MT · 14 mi
590364b
Harlowton, MT · 17 mi
590554b
Melville, MT · 23 mi
590864b
Wilsall, MT · 29 mi
590115a
Big Timber, MT · 30 mi
594534b
Judith Gap, MT · 33 mi
590825a
Springdale, MT · 33 mi
594184b
Buffalo, MT · 37 mi

Montana planting zones →

Questions about 59085

What planting zone is ZIP code 59085?

ZIP code 59085 (Two Dot, MT) is in USDA hardiness zone 4b on the 2023 map: the coldest night of an average winter reaches −25 to −20 °F (−31.7 to −28.9 °C).

When is the last frost in Two Dot, MT?

The median last spring frost (32 °F) near 59085 is June 3; after June 25 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Martinsdale 3 Nnw station.

When is the first frost in Two Dot, MT?

The median first fall frost near 59085 is September 8, giving a median frost-free growing season of 94 days.

When should I plant tomatoes in 59085?

Start tomato seeds indoors around Apr 8 – Apr 22 and set transplants outside around Jun 10 – Jun 24, one to three weeks after the median last frost.

How much rain and snow does 59085 get?

About 13.5 inches of precipitation a year and 43 inches of snowfall (NOAA 1991–2020 normals, Martinsdale 3 Nnw station).

How hot do summers get in Two Dot, MT?

The average high peaks at 83 °F in August, with about 11 days a year at 90 °F or more.

What kind of soil does 59085 have?

The USDA soil survey maps Cabba at the center of ZIP 59085: loam, well drained, pH about 8.1 (alkaline).

Did spring come early in Two Dot, MT in 2026?

Spring leaf-out near 59085 came on Mar 31 in 2026, 29 days earlier than the 1991–2020 average (Apr 29), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Two Dot, MT?

Long-day onions: the longest day near 59085 is 15 h 48 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 59085 change?

Yes. The 2012 USDA map put 59085 in zone 4a; the 2023 map puts it in zone 4b. The newer map uses 1991–2020 data and more weather stations.