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

Planting zone for 59760 — Willow Creek, MT

ZIP code 59760 (Willow Creek, Gallatin County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 26 and the first fall frost September 15.

Where ZIP 59760 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 26

First frostSep 15

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 Willow Creek, 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 Willow Creek, MT

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 26median — 50% chance of a later frost

Safe for tender plantsJune 12only 10% chance of frost after

First fall frostSeptember 15median — 10% chance by Sep 1

Growing season111 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 11 and returns around September 27.

From the NOAA station Logan Landfill, MT — 12 miles away, elevation 4,242 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 59760

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 14 – Apr 28

SpinachSow outdoors · Apr 14 – May 5

Broccoli, cabbageStart indoors · Mar 17 – Mar 31

Broccoli, cabbageTransplant · May 5 – May 19

Onion setsPlant outdoors · Apr 28 – May 12

PotatoesPlant outdoors · May 5 – May 19

LettuceSow outdoors · Apr 28 – May 12

Carrots, beetsSow outdoors · May 5 – May 19

TomatoesStart indoors · Mar 31 – Apr 14

TomatoesTransplant · Jun 2 – Jun 16

Peppers, eggplantStart indoors · Mar 17 – Mar 31

Peppers, eggplantTransplant · Jun 9 – Jun 23

BeansSow outdoors · Jun 2 – Jun 16

Sweet cornSow outdoors · Jun 2 – Jun 16

Cucumbers, squashSow outdoors · Jun 2 – Jun 16

Fall lettuce, spinachSow outdoors · Jul 21 – Aug 4

GarlicPlant cloves · Sep 1 – Oct 6

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 26) and first fall frost (Sep 15) 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 59760 came on Mar 19 — 26 days earlier than the 1991–2020 average (Apr 14).

average
Apr 142026
Mar 19

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 Willow Creek, MT.

Soil in Willow Creek, MT

The soil mapped at the center of ZIP 59760 is Trimad — cobbly loam, well drained.

TextureCobbly loama good balance for most vegetables

pH7.2neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter3%moderate

Hydrologic groupBwater soaks in moderately

Farmland classFarmland of local importanceUSDA classification

Map unit: Trimad cobbly loam, 0 to 4 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 59760; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Willow Creek, MT

Summer high85 °Faverage high, July

Winter low10 °Faverage low, January

Hot days24days a year at 90 °F or more

Freezing nights200nights a year at 32 °F or less

Growing degree days1,612base 50 °F — the season’s usable heat

Longest day15 h 43 mindaylight on June 21

Shortest day8 h 40 mindaylight on December 21

Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)

Precipitation15.5 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Logan Landfill, MT (12 mi away); precipitation: Logan Landfill, MT (12 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5a.

597415a

Manhattan, MT · 11 mi

597455a

Norris, MT · 11 mi

597525a

Three Forks, MT · 12 mi

Mc Allister, MT · 20 mi

597185a

Bozeman, MT · 22 mi

Montana planting zones →

Questions about 59760

What planting zone is ZIP code 59760?

ZIP code 59760 (Willow Creek, 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 Willow Creek, MT?

The median last spring frost (32 °F) near 59760 is May 26; after June 12 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Logan Landfill station.

When is the first frost in Willow Creek, MT?

The median first fall frost near 59760 is September 15, giving a median frost-free growing season of 111 days.

When should I plant tomatoes in 59760?

Start tomato seeds indoors around Mar 31 – Apr 14 and set transplants outside around Jun 2 – Jun 16, one to three weeks after the median last frost.

How much rain and snow does 59760 get?

About 15.5 inches of precipitation a year (NOAA 1991–2020 normals, Logan Landfill station).

How hot do summers get in Willow Creek, MT?

The average high peaks at 85 °F in July, with about 24 days a year at 90 °F or more.

What kind of soil does 59760 have?

The USDA soil survey maps Trimad at the center of ZIP 59760: cobbly loam, well drained, pH about 7.2 (neutral).

Did spring come early in Willow Creek, MT in 2026?

Spring leaf-out near 59760 came on Mar 19 in 2026, 26 days earlier than the 1991–2020 average (Apr 14), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Willow Creek, MT?

Long-day onions: the longest day near 59760 is 15 h 43 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 59760 change?

Yes. The 2012 USDA map put 59760 in zone 4b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.