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

Planting zone for Kalispell, MT

Kalispell, MT is in USDA zone 5b across its 3 ZIP codes. The median last spring frost is May 31 and the first fall frost September 10.

Kalispell on the zone map

Outlined: its 1 ZIP code areas · 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.

Zone5b−15 to −10 °F
ZIP codes3
Last frostMay 31
First frostSep 10
Growing season100 days

5b 3 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Kalispell, 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 Kalispell, MT

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 31median — 50% chance of a later frost
Safe for tender plantsJune 22only 10% chance of frost after
First fall frostSeptember 10median — 10% chance by Aug 26
Growing season100 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 10 and returns around September 27.

From the NOAA station Kalispell Glacier Airport, MT, elevation 2,956 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 Kalispell

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 19 – May 3
SpinachSow outdoors · Apr 19 – May 10
Broccoli, cabbageStart indoors · Mar 22 – Apr 5
Broccoli, cabbageTransplant · May 10 – May 24
Onion setsPlant outdoors · May 3 – May 17
PotatoesPlant outdoors · May 10 – May 24
LettuceSow outdoors · May 3 – May 17
Carrots, beetsSow outdoors · May 10 – May 24
TomatoesStart indoors · Apr 5 – Apr 19
TomatoesTransplant · Jun 7 – Jun 21
Peppers, eggplantStart indoors · Mar 22 – Apr 5
Peppers, eggplantTransplant · Jun 14 – Jun 28
BeansSow outdoors · Jun 7 – Jun 21
Sweet cornSow outdoors · Jun 7 – Jun 21
Cucumbers, squashSow outdoors · Jun 7 – Jun 21
Fall lettuce, spinachSow outdoors · Jul 16 – Jul 30
GarlicPlant cloves · Aug 27 – Oct 1
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 31) and first fall frost (Sep 10) 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 59901 came on Apr 12 — 9 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 5b in Montana

561 plants native to the lower 48 states, recorded in Montana, and rated by the USDA to survive −15 °F or colder — the bottom of zone 5b. Each links to its USDA PLANTS profile.

Trees 28

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 97

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 259

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 164

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 Kalispell, MT.

Soil in Kalispell, MT

The soil mapped at the center of ZIP 59901 is Yeoman — loam, well drained.

TextureLoama good balance for most vegetables
pH6.1slightly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2.5%moderate
Hydrologic groupBwater soaks in moderately
Farmland classPrime farmland if irrigatedUSDA classification

Map unit: Yeoman loam, moderately deep over sand, 0 to 3 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 59901; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Kalispell, MT

Summer high82 °Faverage high, July
Winter low16 °Faverage low, January
Hot days14days a year at 90 °F or more
Freezing nights187nights a year at 32 °F or less
Growing degree days1,425base 50 °F — the season’s usable heat
Longest day16 h 05 mindaylight on June 21
Shortest day8 h 20 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation16.8 inper year, rain and melted snow
Snowfall54 inper year; 75 days with snow on the ground

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 31 °F, low 16 °F 31°16° JanFebruary: average high 36 °F, low 18 °F 36°18° FebMarch: average high 45 °F, low 24 °F 45°24° MarApril: average high 55 °F, low 31 °F 55°31° AprMay: average high 65 °F, low 38 °F 65°38° MayJune: average high 71 °F, low 44 °F 71°44° JunJuly: average high 82 °F, low 48 °F 82°48° JulAugust: average high 82 °F, low 46 °F 82°46° AugSeptember: average high 70 °F, low 38 °F 70°38° SepOctober: average high 54 °F, low 29 °F 54°29° OctNovember: average high 39 °F, low 24 °F 39°24° NovDecember: average high 31 °F, low 17 °F 31°17° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″January: 1.40 in precipitation, 13.9 in snowfall 1.4❄14 JanFebruary: 0.96 in precipitation, 8.4 in snowfall 1.0❄8 FebMarch: 1.11 in precipitation, 5.4 in snowfall 1.1❄5 MarApril: 1.34 in precipitation, 1.2 in snowfall 1.3❄1 AprMay: 1.84 in precipitation, 0.2 in snowfall 1.8 MayJune: 2.84 in precipitation, 0.3 in snowfall 2.8 JunJuly: 1.14 in precipitation 1.1 JulAugust: 0.76 in precipitation 0.8 AugSeptember: 1.17 in precipitation 1.2 SepOctober: 1.35 in precipitation, 1.1 in snowfall 1.4❄1 OctNovember: 1.35 in precipitation, 8 in snowfall 1.4❄8 NovDecember: 1.50 in precipitation, 15.9 in snowfall 1.5❄16 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Kalispell Glacier Airport, MT (8 mi away); precipitation: Kalispell Glacier Airport, MT (8 mi away). Daylight is calculated from latitude.

ZIP codes in Kalispell

599015b
−15 to −10 °F
599035b
−15 to −10 °F
599045b
−15 to −10 °F

Montana planting zones →

Questions about Kalispell

What planting zone is Kalispell, MT?

Kalispell, MT is in USDA hardiness zone 5b on the 2023 map (5b: −15 to −10 °F).

When is the last frost in Kalispell, MT?

The median last spring frost is May 31 and the median first fall frost is September 10 (NOAA 1991–2020 normals, Kalispell Glacier Airport station).

When can I plant a garden in Kalispell, MT?

Cool-season crops like peas and spinach go in around Apr 19 – May 10; tomatoes, peppers, beans and squash after about Jun 7, once frost risk has passed.

What kind of onions grow in Kalispell, MT?

Long-day onions: the longest day is 16 h 05 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

How much rain and snow does Kalispell, MT get?

About 16.8 inches of precipitation a year and 54 inches of snowfall (NOAA 1991–2020 normals).