Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 59937 — Whitefish, MT

ZIP code 59937 (Whitefish, Flathead County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 16 and the first fall frost September 25.

Where ZIP 59937 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 16

First frostSep 25

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 Whitefish, 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 Whitefish, MT

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostMay 16median — 50% chance of a later frost

Safe for tender plantsJune 6only 10% chance of frost after

First fall frostSeptember 25median — 10% chance by Sep 8

Growing season129 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 1 and returns around October 7.

From the NOAA station Whitefish, MT — 7 miles away, elevation 3,101 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 59937

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 4 – Apr 18

SpinachSow outdoors · Apr 4 – Apr 25

Broccoli, cabbageStart indoors · Mar 7 – Mar 21

Broccoli, cabbageTransplant · Apr 25 – May 9

Onion setsPlant outdoors · Apr 18 – May 2

PotatoesPlant outdoors · Apr 25 – May 9

LettuceSow outdoors · Apr 18 – May 2

Carrots, beetsSow outdoors · Apr 25 – May 9

TomatoesStart indoors · Mar 21 – Apr 4

TomatoesTransplant · May 23 – Jun 6

Peppers, eggplantStart indoors · Mar 7 – Mar 21

Peppers, eggplantTransplant · May 30 – Jun 13

BeansSow outdoors · May 23 – Jun 6

Sweet cornSow outdoors · May 23 – Jun 6

Cucumbers, squashSow outdoors · May 23 – Jun 6

Fall lettuce, spinachSow outdoors · Jul 31 – Aug 14

GarlicPlant cloves · Sep 11 – Oct 16

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 16) and first fall frost (Sep 25) 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 59937 came on Apr 18 — 7 days earlier than the 1991–2020 average (Apr 25).

average
Apr 252026
Apr 18

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.

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 Whitefish, MT.

Soil in Whitefish, MT

The soil mapped at the center of ZIP 59937 is Andeptic Cryoboralfs — silt loam.

TextureSilt loama good balance for most vegetables

pH5.4strongly acidic; most vegetables like 6.0–7.0

Organic matter2%moderate

Hydrologic groupCwater soaks in slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Andeptic Cryoboralfs-Andic Cryochrepts complex, hilly.

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 59937; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Whitefish, MT

Summer high81 °Faverage high, July

Winter low16 °Faverage low, January

Hot days13days a year at 90 °F or more

Freezing nights195nights a year at 32 °F or less

Growing degree days1,456base 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)

Precipitation19.9 inper year, rain and melted snow

Snowfall63 inper year; 124 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

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

Nearby ZIP codes

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

599275a

Olney, MT · 13 mi

599015b

Kalispell, MT · 15 mi

599035b

Kalispell, MT · 15 mi

599125a

Columbia Falls, MT · 15 mi

599045b

Kalispell, MT · 18 mi

599195b

Hungry Horse, MT · 21 mi

Montana planting zones →

Questions about 59937

What planting zone is ZIP code 59937?

ZIP code 59937 (Whitefish, 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 Whitefish, MT?

The median last spring frost (32 °F) near 59937 is May 16; after June 6 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Whitefish station.

When is the first frost in Whitefish, MT?

The median first fall frost near 59937 is September 25, giving a median frost-free growing season of 129 days.

When should I plant tomatoes in 59937?

Start tomato seeds indoors around Mar 21 – Apr 4 and set transplants outside around May 23 – Jun 6, one to three weeks after the median last frost.

How much rain and snow does 59937 get?

About 19.9 inches of precipitation a year and 63 inches of snowfall (NOAA 1991–2020 normals, Whitefish station).

How hot do summers get in Whitefish, MT?

The average high peaks at 81 °F in July, with about 13 days a year at 90 °F or more.

What kind of soil does 59937 have?

The USDA soil survey maps Andeptic Cryoboralfs at the center of ZIP 59937: silt loam, pH about 5.4 (strongly acidic).

Did spring come early in Whitefish, MT in 2026?

Spring leaf-out near 59937 came on Apr 18 in 2026, 7 days earlier than the 1991–2020 average (Apr 25), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Whitefish, MT?

Long-day onions: the longest day near 59937 is 16 h 07 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).