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

Planting zone for 59301 — Miles City, MT

ZIP code 59301 (Miles City, Custer County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is May 8 and the first fall frost September 30.

Where ZIP 59301 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 frostMay 8
First frostSep 30
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 Miles City, 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 Miles City, MT

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 8median — 50% chance of a later frost
Safe for tender plantsMay 21only 10% chance of frost after
First fall frostSeptember 30median — 10% chance by Sep 17
Growing season144 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 29 and returns around October 8.

From the NOAA station Miles City F Wiley Field, MT — 4 miles away, elevation 2,625 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 59301

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 27 – Apr 10
SpinachSow outdoors · Mar 27 – Apr 17
Broccoli, cabbageStart indoors · Feb 27 – Mar 13
Broccoli, cabbageTransplant · Apr 17 – May 1
Onion setsPlant outdoors · Apr 10 – Apr 24
PotatoesPlant outdoors · Apr 17 – May 1
LettuceSow outdoors · Apr 10 – Apr 24
Carrots, beetsSow outdoors · Apr 17 – May 1
TomatoesStart indoors · Mar 13 – Mar 27
TomatoesTransplant · May 15 – May 29
Peppers, eggplantStart indoors · Feb 27 – Mar 13
Peppers, eggplantTransplant · May 22 – Jun 5
BeansSow outdoors · May 15 – May 29
Sweet cornSow outdoors · May 15 – May 29
Cucumbers, squashSow outdoors · May 15 – May 29
Fall lettuce, spinachSow outdoors · Aug 5 – Aug 19
GarlicPlant cloves · Sep 16 – Oct 21
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 8) and first fall frost (Sep 30) 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 59301 came on Mar 23 — 15 days earlier than the 1991–2020 average (Apr 7).

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 Miles City, MT.

Soil in Miles City, MT

The soil mapped at the center of ZIP 59301 is Cabbart — loam, well drained.

TextureLoama good balance for most vegetables
pH8.2alkaline; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.5%low — add compost
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Cabbart-Rock outcrop-Yawdim complex, warm, 15 to 70 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 59301; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Miles City, MT

Summer high89 °Faverage high, July
Winter low9 °Faverage low, January
Hot days41days a year at 90 °F or more
Freezing nights166nights a year at 32 °F or less
Growing degree days2,630base 50 °F — the season’s usable heat
Longest day15 h 48 mindaylight on June 21
Shortest day8 h 35 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation12.9 inper year, rain and melted snow

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 30 °F, low 9 °F 30°9° JanFebruary: average high 35 °F, low 13 °F 35°13° FebMarch: average high 47 °F, low 23 °F 47°23° MarApril: average high 58 °F, low 33 °F 58°33° AprMay: average high 68 °F, low 43 °F 68°43° MayJune: average high 79 °F, low 53 °F 79°53° JunJuly: average high 89 °F, low 60 °F 89°60° JulAugust: average high 87 °F, low 58 °F 87°58° AugSeptember: average high 76 °F, low 47 °F 76°47° SepOctober: average high 59 °F, low 34 °F 59°34° OctNovember: average high 44 °F, low 21 °F 44°21° NovDecember: average high 33 °F, low 12 °F 33°12° Dec

Precipitation by month inches

0″1″2″3″January: 0.28 in precipitation 0.3 JanFebruary: 0.26 in precipitation 0.3 FebMarch: 0.55 in precipitation 0.6 MarApril: 1.54 in precipitation 1.5 AprMay: 2.73 in precipitation 2.7 MayJune: 2.51 in precipitation 2.5 JunJuly: 1.51 in precipitation 1.5 JulAugust: 0.91 in precipitation 0.9 AugSeptember: 1.07 in precipitation 1.1 SepOctober: 0.97 in precipitation 1.0 OctNovember: 0.33 in precipitation 0.3 NovDecember: 0.22 in precipitation 0.2 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Miles City F Wiley Field, MT (4 mi away); precipitation: Miles City F Wiley Field, MT (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

593334a
Hathaway, MT · 17 mi
593384a
Kinsey, MT · 22 mi
593474b
Rosebud, MT · 24 mi
593494a
Terry, MT · 36 mi
593274b
Forsyth, MT · 40 mi
593514b
Volborg, MT · 42 mi
593454b
Powderville, MT · 47 mi
593124a
Angela, MT · 50 mi

Montana planting zones →

Questions about 59301

What planting zone is ZIP code 59301?

ZIP code 59301 (Miles City, 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 Miles City, MT?

The median last spring frost (32 °F) near 59301 is May 8; after May 21 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Miles City F Wiley Field station.

When is the first frost in Miles City, MT?

The median first fall frost near 59301 is September 30, giving a median frost-free growing season of 144 days.

When should I plant tomatoes in 59301?

Start tomato seeds indoors around Mar 13 – Mar 27 and set transplants outside around May 15 – May 29, one to three weeks after the median last frost.

How much rain and snow does 59301 get?

About 12.9 inches of precipitation a year (NOAA 1991–2020 normals, Miles City F Wiley Field station).

How hot do summers get in Miles City, MT?

The average high peaks at 89 °F in July, with about 41 days a year at 90 °F or more.

What kind of soil does 59301 have?

The USDA soil survey maps Cabbart at the center of ZIP 59301: loam, well drained, pH about 8.2 (alkaline).

Did spring come early in Miles City, MT in 2026?

Spring leaf-out near 59301 came on Mar 23 in 2026, 15 days earlier than the 1991–2020 average (Apr 7), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Miles City, MT?

Long-day onions: the longest day near 59301 is 15 h 48 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 59301 change?

Yes. The 2012 USDA map put 59301 in zone 4a; the 2023 map puts it in zone 4b. The newer map uses 1991–2020 data and more weather stations.