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

Planting zone for 59756 — Warm Springs, MT

ZIP code 59756 (Warm Springs, Deer Lodge County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is June 1 and the first fall frost September 14.

Where ZIP 59756 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 1
First frostSep 14
2012 zone4b

Same zone as on the 2012 map. 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 Warm Springs, 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 Warm Springs, MT

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostJune 1median — 50% chance of a later frost
Safe for tender plantsJune 25only 10% chance of frost after
First fall frostSeptember 14median — 10% chance by Aug 31
Growing season105 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 13 and returns around September 28.

From the NOAA station Anaconda, MT — 6 miles away, elevation 5,230 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 59756

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 20 – May 4
SpinachSow outdoors · Apr 20 – May 11
Broccoli, cabbageStart indoors · Mar 23 – Apr 6
Broccoli, cabbageTransplant · May 11 – May 25
Onion setsPlant outdoors · May 4 – May 18
PotatoesPlant outdoors · May 11 – May 25
LettuceSow outdoors · May 4 – May 18
Carrots, beetsSow outdoors · May 11 – May 25
TomatoesStart indoors · Apr 6 – Apr 20
TomatoesTransplant · Jun 8 – Jun 22
Peppers, eggplantStart indoors · Mar 23 – Apr 6
Peppers, eggplantTransplant · Jun 15 – Jun 29
BeansSow outdoors · Jun 8 – Jun 22
Sweet cornSow outdoors · Jun 8 – Jun 22
Cucumbers, squashSow outdoors · Jun 8 – Jun 22
Fall lettuce, spinachSow outdoors · Jul 20 – Aug 3
GarlicPlant cloves · Aug 31 – Oct 5
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jun 1) and first fall frost (Sep 14) 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 59756 came on Mar 23 — 29 days earlier than the 1991–2020 average (Apr 21).

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 Warm Springs, MT.

Soil in Warm Springs, MT

The soil mapped at the center of ZIP 59756 is Pozega — silty clay loam, somewhat poorly drained.

TextureSilty clay loamholds water and nutrients; slow to drain and warm up
pH8.6alkaline; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter7%high
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Pozega silty clay loam, 0 to 4 percent slopes, moderately impacted.

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 59756; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Warm Springs, MT

Summer high83 °Faverage high, July
Winter low15 °Faverage low, December
Hot days10days a year at 90 °F or more
Freezing nights201nights a year at 32 °F or less
Growing degree days1,559base 50 °F — the season’s usable heat
Longest day15 h 47 mindaylight on June 21
Shortest day8 h 37 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation14.9 inper year, rain and melted snow
Snowfall75 inper year; 98 days with snow on the ground

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 16 °F 39°16° FebMarch: average high 48 °F, low 23 °F 48°23° MarApril: average high 55 °F, low 28 °F 55°28° AprMay: average high 64 °F, low 36 °F 64°36° MayJune: average high 73 °F, low 43 °F 73°43° JunJuly: average high 83 °F, low 49 °F 83°49° JulAugust: average high 82 °F, low 47 °F 82°47° AugSeptember: average high 72 °F, low 40 °F 72°40° SepOctober: average high 57 °F, low 31 °F 57°31° OctNovember: average high 43 °F, low 21 °F 43°21° NovDecember: average high 34 °F, low 15 °F 34°15° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″January: 0.57 in precipitation, 11.4 in snowfall 0.6❄11 JanFebruary: 0.99 in precipitation, 11.3 in snowfall 1.0❄11 FebMarch: 1.15 in precipitation, 11.8 in snowfall 1.1❄12 MarApril: 1.50 in precipitation, 9.9 in snowfall 1.5❄10 AprMay: 2.13 in precipitation, 2 in snowfall 2.1❄2 MayJune: 2.21 in precipitation, 0.6 in snowfall 2.2❄1 JunJuly: 1.30 in precipitation 1.3 JulAugust: 1.20 in precipitation, 0.2 in snowfall 1.2 AugSeptember: 1.15 in precipitation, 0.4 in snowfall 1.1 SepOctober: 1.00 in precipitation, 3.3 in snowfall 1.0❄3 OctNovember: 0.97 in precipitation, 12.1 in snowfall 1.0❄12 NovDecember: 0.72 in precipitation, 12.1 in snowfall 0.7❄12 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Anaconda, MT (6 mi away); precipitation: Anaconda, MT (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

597484b
Ramsay, MT · 11 mi
597224b
Deer Lodge, MT · 13 mi
597115a
Anaconda, MT · 16 mi
597074b
Butte, MT · 19 mi
597505a
Butte, MT · 19 mi
597015a
Butte, MT · 20 mi
597024a
Butte, MT · 21 mi
597034a
Butte, MT · 21 mi

Montana planting zones →

Questions about 59756

What planting zone is ZIP code 59756?

ZIP code 59756 (Warm Springs, 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 Warm Springs, MT?

The median last spring frost (32 °F) near 59756 is June 1; after June 25 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Anaconda station.

When is the first frost in Warm Springs, MT?

The median first fall frost near 59756 is September 14, giving a median frost-free growing season of 105 days.

When should I plant tomatoes in 59756?

Start tomato seeds indoors around Apr 6 – Apr 20 and set transplants outside around Jun 8 – Jun 22, one to three weeks after the median last frost.

How much rain and snow does 59756 get?

About 14.9 inches of precipitation a year and 75 inches of snowfall (NOAA 1991–2020 normals, Anaconda station).

How hot do summers get in Warm Springs, MT?

The average high peaks at 83 °F in July, with about 10 days a year at 90 °F or more.

What kind of soil does 59756 have?

The USDA soil survey maps Pozega at the center of ZIP 59756: silty clay loam, somewhat poorly drained, pH about 8.6 (alkaline).

Did spring come early in Warm Springs, MT in 2026?

Spring leaf-out near 59756 came on Mar 23 in 2026, 29 days earlier than the 1991–2020 average (Apr 21), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Warm Springs, MT?

Long-day onions: the longest day near 59756 is 15 h 47 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).