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

Planting zone for 59913 — Coram, MT

ZIP code 59913 (Coram, Flathead County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 18 and the first fall frost September 20.

Where ZIP 59913 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 frostMay 18
First frostSep 20
2012 zone5a

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 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Coram, 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 Coram, MT

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 18median — 50% chance of a later frost
Safe for tender plantsJune 4only 10% chance of frost after
First fall frostSeptember 20median — 10% chance by Sep 3
Growing season124 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 1 and returns around October 4.

From the NOAA station W Glacier, MT — 5 miles away, elevation 3,150 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 59913

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 6 – Apr 20
SpinachSow outdoors · Apr 6 – Apr 27
Broccoli, cabbageStart indoors · Mar 9 – Mar 23
Broccoli, cabbageTransplant · Apr 27 – May 11
Onion setsPlant outdoors · Apr 20 – May 4
PotatoesPlant outdoors · Apr 27 – May 11
LettuceSow outdoors · Apr 20 – May 4
Carrots, beetsSow outdoors · Apr 27 – May 11
TomatoesStart indoors · Mar 23 – Apr 6
TomatoesTransplant · May 25 – Jun 8
Peppers, eggplantStart indoors · Mar 9 – Mar 23
Peppers, eggplantTransplant · Jun 1 – Jun 15
BeansSow outdoors · May 25 – Jun 8
Sweet cornSow outdoors · May 25 – Jun 8
Cucumbers, squashSow outdoors · May 25 – Jun 8
Fall lettuce, spinachSow outdoors · Jul 26 – Aug 9
GarlicPlant cloves · Sep 6 – Oct 11
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 18) and first fall frost (Sep 20) 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 59913 came on May 3 — 7 days earlier than the 1991–2020 average (May 10).

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 Coram, MT.

Soil in Coram, MT

The soil mapped at the center of ZIP 59913 is Ochrepts — slightly decomposed plant material.

TextureSlightly decomposed plant materialtop layer
pH6.5neutral; most vegetables like 6.0–7.0
Organic matter50%high
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Ochrepts-Rock outcrop complex, structural breaklands.

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 59913; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Coram, MT

Summer high80 °Faverage high, July
Winter low19 °Faverage low, January
Hot days7days a year at 90 °F or more
Freezing nights180nights a year at 32 °F or less
Growing degree days1,429base 50 °F — the season’s usable heat
Longest day16 h 07 mindaylight on June 21
Shortest day8 h 18 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation40.8 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 30 °F, low 19 °F 30°19° JanFebruary: average high 34 °F, low 19 °F 34°19° FebMarch: average high 43 °F, low 25 °F 43°25° MarApril: average high 53 °F, low 31 °F 53°31° AprMay: average high 64 °F, low 39 °F 64°39° MayJune: average high 70 °F, low 45 °F 70°45° JunJuly: average high 80 °F, low 50 °F 80°50° JulAugust: average high 79 °F, low 48 °F 79°48° AugSeptember: average high 68 °F, low 41 °F 68°41° SepOctober: average high 52 °F, low 33 °F 52°33° OctNovember: average high 37 °F, low 26 °F 37°26° NovDecember: average high 29 °F, low 20 °F 29°20° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 4.60 in precipitation 4.6 JanFebruary: 3.18 in precipitation 3.2 FebMarch: 3.95 in precipitation 4.0 MarApril: 3.32 in precipitation 3.3 AprMay: 3.49 in precipitation 3.5 MayJune: 4.50 in precipitation 4.5 JunJuly: 1.50 in precipitation 1.5 JulAugust: 1.39 in precipitation 1.4 AugSeptember: 2.42 in precipitation 2.4 SepOctober: 3.64 in precipitation 3.6 OctNovember: 4.36 in precipitation 4.4 NovDecember: 4.40 in precipitation 4.4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: W Glacier, MT (5 mi away); precipitation: Emery Creek, MT (within 1 mile). 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.

599265b
Martin City, MT · 6 mi
599195b
Hungry Horse, MT · 6 mi
599215a
Lake Mc Donald, MT · 9 mi
599125a
Columbia Falls, MT · 10 mi
599165a
Essex, MT · 16 mi
599045b
Kalispell, MT · 19 mi
599375a
Whitefish, MT · 25 mi
599015b
Kalispell, MT · 25 mi

Montana planting zones →

Questions about 59913

What planting zone is ZIP code 59913?

ZIP code 59913 (Coram, 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 Coram, MT?

The median last spring frost (32 °F) near 59913 is May 18; after June 4 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, W Glacier station.

When is the first frost in Coram, MT?

The median first fall frost near 59913 is September 20, giving a median frost-free growing season of 124 days.

When should I plant tomatoes in 59913?

Start tomato seeds indoors around Mar 23 – Apr 6 and set transplants outside around May 25 – Jun 8, one to three weeks after the median last frost.

How much rain and snow does 59913 get?

About 40.8 inches of precipitation a year (NOAA 1991–2020 normals, Emery Creek station).

How hot do summers get in Coram, MT?

The average high peaks at 80 °F in July, with about 7 days a year at 90 °F or more.

What kind of soil does 59913 have?

The USDA soil survey maps Ochrepts at the center of ZIP 59913: slightly decomposed plant material, pH about 6.5 (neutral).

Did spring come early in Coram, MT in 2026?

Spring leaf-out near 59913 came on May 3 in 2026, 7 days earlier than the 1991–2020 average (May 10), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Coram, MT?

Long-day onions: the longest day near 59913 is 16 h 07 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).