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

Planting zone for 59702 — Butte, MT

ZIP code 59702 (Butte, Silver Bow County) is in USDA zone 4a: the coldest winter night averages −30 to −25 °F. The median last spring frost is June 13 and the first fall frost September 5.

Where ZIP 59702 is

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.

Zone4a−30 to −25 °F
Coldest night−34.4 to −31.7 °C
Last frostJun 13
First frostSep 5
2012 zone4a

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 4a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Butte, 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 Butte, MT

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostJune 13median — 50% chance of a later frost
Safe for tender plantsJuly 1only 10% chance of frost after
First fall frostSeptember 5median — 10% chance by Aug 24
Growing season83 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 21 and returns around September 17.

From the NOAA station Butte Bert Mooney Airport, MT — 7 miles away, elevation 5,506 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 59702

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · May 2 – May 16
SpinachSow outdoors · May 2 – May 23
Broccoli, cabbageStart indoors · Apr 4 – Apr 18
Broccoli, cabbageTransplant · May 23 – Jun 6
Onion setsPlant outdoors · May 16 – May 30
PotatoesPlant outdoors · May 23 – Jun 6
LettuceSow outdoors · May 16 – May 30
Carrots, beetsSow outdoors · May 23 – Jun 6
TomatoesStart indoors · Apr 18 – May 2
TomatoesTransplant · Jun 20 – Jul 4
Peppers, eggplantStart indoors · Apr 4 – Apr 18
Peppers, eggplantTransplant · Jun 27 – Jul 11
BeansSow outdoors · Jun 20 – Jul 4
Sweet cornSow outdoors · Jun 20 – Jul 4
Cucumbers, squashSow outdoors · Jun 20 – Jul 4
Fall lettuce, spinachSow outdoors · Jul 11 – Jul 25
GarlicPlant cloves · Aug 22 – Sep 26
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jun 13) and first fall frost (Sep 5) 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 59702 came on Apr 18 — 18 days earlier than the 1991–2020 average (May 6).

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 4a in Montana

439 plants native to the lower 48 states, recorded in Montana, and rated by the USDA to survive −30 °F or colder — the bottom of zone 4a. Each links to its USDA PLANTS profile.

Trees 21

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 77

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °Falderleaf mountain mahogany15 ft · blooms late spring · medium shade tolerance · to −41 °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 °FBarclay's willow15 ft · high shade tolerance · to −43 °F

Wildflowers & perennials 189

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 bistort1.5 ft · blooms mid spring · high shade tolerance · to −38 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °F

Grasses 141

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 Butte, MT.

Soil in Butte, MT

The soil mapped at the center of ZIP 59702 is Moosejaw — mucky peat, very poorly drained.

TextureMucky peattop layer
pH6.5neutral; most vegetables like 6.0–7.0
DrainageVery poorly drainedconsider raised beds
Organic matter70%high
Hydrologic groupA/Ddrains fast once dried out; wet otherwise
Farmland classNot prime farmlandUSDA classification

Map unit: Moosejaw, occasionally flooded-Highrye-Silas, occasionally flooded complex, 2 to 12 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 59702; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Butte, MT

Summer high81 °Faverage high, July
Winter low7 °Faverage low, December
Hot days8days a year at 90 °F or more
Freezing nights220nights a year at 32 °F or less
Growing degree days1,210base 50 °F — the season’s usable heat
Longest day15 h 44 mindaylight on June 21
Shortest day8 h 39 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation12.8 inper year, rain and melted snow

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 32 °F, low 8 °F 32°8° JanFebruary: average high 35 °F, low 10 °F 35°10° FebMarch: average high 44 °F, low 19 °F 44°19° MarApril: average high 51 °F, low 26 °F 51°26° AprMay: average high 61 °F, low 34 °F 61°34° MayJune: average high 70 °F, low 41 °F 70°41° JunJuly: average high 81 °F, low 46 °F 81°46° JulAugust: average high 80 °F, low 44 °F 80°44° AugSeptember: average high 69 °F, low 37 °F 69°37° SepOctober: average high 54 °F, low 27 °F 54°27° OctNovember: average high 40 °F, low 16 °F 40°16° NovDecember: average high 31 °F, low 7 °F 31°7° Dec

Precipitation by month inches

0″1″2″3″January: 0.42 in precipitation 0.4 JanFebruary: 0.43 in precipitation 0.4 FebMarch: 0.64 in precipitation 0.6 MarApril: 1.33 in precipitation 1.3 AprMay: 2.02 in precipitation 2.0 MayJune: 2.45 in precipitation 2.5 JunJuly: 1.20 in precipitation 1.2 JulAugust: 1.28 in precipitation 1.3 AugSeptember: 1.07 in precipitation 1.1 SepOctober: 0.84 in precipitation 0.8 OctNovember: 0.60 in precipitation 0.6 NovDecember: 0.48 in precipitation 0.5 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Butte Bert Mooney Airport, MT (7 mi away); precipitation: Butte Bert Mooney Airport, MT (7 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

597034a
Butte, MT · <1 mi
597505a
Butte, MT · 2 mi
597074b
Butte, MT · 8 mi
597484b
Ramsay, MT · 10 mi
597275a
Divide, MT · 12 mi
597015a
Butte, MT · 12 mi
597564b
Warm Springs, MT · 21 mi
597435a
Melrose, MT · 22 mi

All 5 ZIP codes in Butte → · Montana planting zones →

Questions about 59702

What planting zone is ZIP code 59702?

ZIP code 59702 (Butte, MT) is in USDA hardiness zone 4a on the 2023 map: the coldest night of an average winter reaches −30 to −25 °F (−34.4 to −31.7 °C).

When is the last frost in Butte, MT?

The median last spring frost (32 °F) near 59702 is June 13; after July 1 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Butte Bert Mooney Airport station.

When is the first frost in Butte, MT?

The median first fall frost near 59702 is September 5, giving a median frost-free growing season of 83 days.

When should I plant tomatoes in 59702?

Start tomato seeds indoors around Apr 18 – May 2 and set transplants outside around Jun 20 – Jul 4, one to three weeks after the median last frost.

How much rain and snow does 59702 get?

About 12.8 inches of precipitation a year (NOAA 1991–2020 normals, Butte Bert Mooney Airport station).

How hot do summers get in Butte, MT?

The average high peaks at 81 °F in July, with about 8 days a year at 90 °F or more.

What kind of soil does 59702 have?

The USDA soil survey maps Moosejaw at the center of ZIP 59702: mucky peat, very poorly drained, pH about 6.5 (neutral).

Did spring come early in Butte, MT in 2026?

Spring leaf-out near 59702 came on Apr 18 in 2026, 18 days earlier than the 1991–2020 average (May 6), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Butte, MT?

Long-day onions: the longest day near 59702 is 15 h 44 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).