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

Planting zone for 59743 — Melrose, MT

ZIP code 59743 (Melrose, Silver Bow County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is June 10 and the first fall frost September 7.

Where ZIP 59743 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.

Zone5a−20 to −15 °F
Coldest night−28.9 to −26.1 °C
Last frostJun 10
First frostSep 7
2012 zone4b

Was 4b 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 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Melrose, 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 Melrose, MT

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostJune 10median — 50% chance of a later frost
Safe for tender plantsJuly 2only 10% chance of frost after
First fall frostSeptember 7median — 10% chance by Aug 24
Growing season85 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 21 and returns around September 19.

From the NOAA station Divide, MT — 11 miles away, elevation 5,351 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 59743

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 29 – May 13
SpinachSow outdoors · Apr 29 – May 20
Broccoli, cabbageStart indoors · Apr 1 – Apr 15
Broccoli, cabbageTransplant · May 20 – Jun 3
Onion setsPlant outdoors · May 13 – May 27
PotatoesPlant outdoors · May 20 – Jun 3
LettuceSow outdoors · May 13 – May 27
Carrots, beetsSow outdoors · May 20 – Jun 3
TomatoesStart indoors · Apr 15 – Apr 29
TomatoesTransplant · Jun 17 – Jul 1
Peppers, eggplantStart indoors · Apr 1 – Apr 15
Peppers, eggplantTransplant · Jun 24 – Jul 8
BeansSow outdoors · Jun 17 – Jul 1
Sweet cornSow outdoors · Jun 17 – Jul 1
Cucumbers, squashSow outdoors · Jun 17 – Jul 1
Fall lettuce, spinachSow outdoors · Jul 13 – Jul 27
GarlicPlant cloves · Aug 24 – Sep 28
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jun 10) and first fall frost (Sep 7) 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 59743 came on Apr 11 — 20 days earlier than the 1991–2020 average (May 1).

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 5a in Montana

548 plants native to the lower 48 states, recorded in Montana, and rated by the USDA to survive −20 °F or colder — the bottom of zone 5a. Each links to its USDA PLANTS profile.

Trees 26

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 96

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 253

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 161

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 Melrose, MT.

Soil in Melrose, MT

The soil mapped at the center of ZIP 59743 is Libeg — gravelly loam, well drained.

TextureGravelly loama good balance for most vegetables
pH7.0neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter6%high
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Libeg-Nieman, stony complex, 8 to 25 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 59743; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Melrose, MT

Summer high86 °Faverage high, July
Winter low8 °Faverage low, January
Hot days22days a year at 90 °F or more
Freezing nights213nights a year at 32 °F or less
Growing degree days1,422base 50 °F — the season’s usable heat
Longest day15 h 42 mindaylight on June 21
Shortest day8 h 41 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation9.2 inper year, rain and melted snow
Snowfall10 inper year; 29 days with snow on the ground

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 37 °F, low 8 °F 37°8° JanFebruary: average high 41 °F, low 11 °F 41°11° FebMarch: average high 50 °F, low 19 °F 50°19° MarApril: average high 58 °F, low 26 °F 58°26° AprMay: average high 68 °F, low 33 °F 68°33° MayJune: average high 76 °F, low 40 °F 76°40° JunJuly: average high 86 °F, low 44 °F 86°44° JulAugust: average high 85 °F, low 41 °F 85°41° AugSeptember: average high 76 °F, low 33 °F 76°33° SepOctober: average high 61 °F, low 25 °F 61°25° OctNovember: average high 45 °F, low 15 °F 45°15° NovDecember: average high 36 °F, low 8 °F 36°8° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″January: 0.24 in precipitation, 2 in snowfall 0.2❄2 JanFebruary: 0.39 in precipitation, 1.2 in snowfall 0.4❄1 FebMarch: 0.47 in precipitation, 1.2 in snowfall 0.5❄1 MarApril: 0.83 in precipitation, 1.1 in snowfall 0.8❄1 AprMay: 1.74 in precipitation 1.7 MayJune: 1.67 in precipitation 1.7 JunJuly: 0.83 in precipitation 0.8 JulAugust: 0.85 in precipitation 0.8 AugSeptember: 0.71 in precipitation 0.7 SepOctober: 0.68 in precipitation, 0.3 in snowfall 0.7 OctNovember: 0.46 in precipitation, 1.8 in snowfall 0.5❄2 NovDecember: 0.31 in precipitation, 2.5 in snowfall 0.3❄3 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Glen 4 N, MT (6 mi away); precipitation: Glen 4 N, MT (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

597324b
Glen, MT · 8 mi
597275a
Divide, MT · 14 mi
597545a
Twin Bridges, MT · 21 mi
597465a
Polaris, MT · 21 mi
597024a
Butte, MT · 22 mi
597034a
Butte, MT · 22 mi
597505a
Butte, MT · 22 mi
597515a
Silver Star, MT · 23 mi

Montana planting zones →

Questions about 59743

What planting zone is ZIP code 59743?

ZIP code 59743 (Melrose, MT) is in USDA hardiness zone 5a on the 2023 map: the coldest night of an average winter reaches −20 to −15 °F (−28.9 to −26.1 °C).

When is the last frost in Melrose, MT?

The median last spring frost (32 °F) near 59743 is June 10; after July 2 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Divide station.

When is the first frost in Melrose, MT?

The median first fall frost near 59743 is September 7, giving a median frost-free growing season of 85 days.

When should I plant tomatoes in 59743?

Start tomato seeds indoors around Apr 15 – Apr 29 and set transplants outside around Jun 17 – Jul 1, one to three weeks after the median last frost.

How much rain and snow does 59743 get?

About 9.2 inches of precipitation a year and 10 inches of snowfall (NOAA 1991–2020 normals, Glen 4 N station).

How hot do summers get in Melrose, MT?

The average high peaks at 86 °F in July, with about 22 days a year at 90 °F or more.

What kind of soil does 59743 have?

The USDA soil survey maps Libeg at the center of ZIP 59743: gravelly loam, well drained, pH about 7.0 (neutral).

Did spring come early in Melrose, MT in 2026?

Spring leaf-out near 59743 came on Apr 11 in 2026, 20 days earlier than the 1991–2020 average (May 1), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Melrose, MT?

Long-day onions: the longest day near 59743 is 15 h 42 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 59743 change?

Yes. The 2012 USDA map put 59743 in zone 4b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.