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

Planting zone for 59825 — Clinton, MT

ZIP code 59825 (Clinton, Missoula County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is May 22 and the first fall frost September 19.

Where ZIP 59825 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.

Zone5b−15 to −10 °F

Coldest night−26.1 to −23.3 °C

Last frostMay 22

First frostSep 19

2012 zone4b

Was 4b on the 2012 map — a full zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 5b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Clinton, 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 Clinton, MT

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 22median — 50% chance of a later frost

Safe for tender plantsJune 13only 10% chance of frost after

First fall frostSeptember 19median — 10% chance by Sep 3

Growing season115 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 5 and returns around October 1.

From the NOAA station Stevensville, MT — 22 miles away, elevation 3,376 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 59825

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 10 – Apr 24

SpinachSow outdoors · Apr 10 – May 1

Broccoli, cabbageStart indoors · Mar 13 – Mar 27

Broccoli, cabbageTransplant · May 1 – May 15

Onion setsPlant outdoors · Apr 24 – May 8

PotatoesPlant outdoors · May 1 – May 15

LettuceSow outdoors · Apr 24 – May 8

Carrots, beetsSow outdoors · May 1 – May 15

TomatoesStart indoors · Mar 27 – Apr 10

TomatoesTransplant · May 29 – Jun 12

Peppers, eggplantStart indoors · Mar 13 – Mar 27

Peppers, eggplantTransplant · Jun 5 – Jun 19

BeansSow outdoors · May 29 – Jun 12

Sweet cornSow outdoors · May 29 – Jun 12

Cucumbers, squashSow outdoors · May 29 – Jun 12

Fall lettuce, spinachSow outdoors · Jul 25 – Aug 8

GarlicPlant cloves · Sep 5 – Oct 10

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 22) and first fall frost (Sep 19) 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 59825 came on Apr 11 — 16 days earlier than the 1991–2020 average (Apr 27).

average
Apr 272026
Apr 11

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.

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 Clinton, MT.

Soil in Clinton, MT

The soil mapped at the center of ZIP 59825 is Beehive — slightly decomposed plant material, somewhat poorly drained.

TextureSlightly decomposed plant materialtop layer

pH5.0strongly acidic; most vegetables like 6.0–7.0

DrainageSomewhat poorly drainedconsider raised beds

Organic matter75%high

Hydrologic groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Beehive-Moosehead-Kawuneeche families, complex, stream bottoms.

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 59825; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Clinton, MT

Summer high82 °Faverage high, July

Winter low8 °Faverage low, January

Hot days16days a year at 90 °F or more

Freezing nights247nights a year at 32 °F or less

Growing degree days1,019base 50 °F — the season’s usable heat

Longest day15 h 50 mindaylight on June 21

Shortest day8 h 33 mindaylight on December 21

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

Precipitation20.1 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: Potomac, MT (19 mi away); precipitation: Combination, MT (16 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

Philipsburg, MT · 24 mi

Montana planting zones →

Questions about 59825

What planting zone is ZIP code 59825?

ZIP code 59825 (Clinton, MT) is in USDA hardiness zone 5b on the 2023 map: the coldest night of an average winter reaches −15 to −10 °F (−26.1 to −23.3 °C).

When is the last frost in Clinton, MT?

The median last spring frost (32 °F) near 59825 is May 22; after June 13 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Stevensville station.

When is the first frost in Clinton, MT?

The median first fall frost near 59825 is September 19, giving a median frost-free growing season of 115 days.

When should I plant tomatoes in 59825?

Start tomato seeds indoors around Mar 27 – Apr 10 and set transplants outside around May 29 – Jun 12, one to three weeks after the median last frost.

How much rain and snow does 59825 get?

About 20.1 inches of precipitation a year (NOAA 1991–2020 normals, Combination station).

How hot do summers get in Clinton, MT?

The average high peaks at 82 °F in July, with about 16 days a year at 90 °F or more.

What kind of soil does 59825 have?

The USDA soil survey maps Beehive at the center of ZIP 59825: slightly decomposed plant material, somewhat poorly drained, pH about 5.0 (strongly acidic).

Did spring come early in Clinton, MT in 2026?

Spring leaf-out near 59825 came on Apr 11 in 2026, 16 days earlier than the 1991–2020 average (Apr 27), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Clinton, MT?

Long-day onions: the longest day near 59825 is 15 h 50 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 59825 change?

Yes. The 2012 USDA map put 59825 in zone 4b; the 2023 map puts it in zone 5b. The newer map uses 1991–2020 data and more weather stations.