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

Planting zone for 59316 — Boyes, MT

ZIP code 59316 (Boyes, Carter County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is May 16 and the first fall frost September 28.

Where ZIP 59316 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.

Zone4b−25 to −20 °F
Coldest night−31.7 to −28.9 °C
Last frostMay 16
First frostSep 28
2012 zone4a

Was 4a 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 4b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Boyes, 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 Boyes, 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 plantsMay 29only 10% chance of frost after
First fall frostSeptember 28median — 10% chance by Sep 13
Growing season135 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 3 and returns around October 7.

From the NOAA station Broadus, MT — 17 miles away, elevation 3,032 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 59316

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 · Aug 3 – Aug 17
GarlicPlant cloves · Sep 14 – Oct 19
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 16) and first fall frost (Sep 28) 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 59316 came on Mar 23 — 18 days earlier than the 1991–2020 average (Apr 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 4b in Montana

506 plants native to the lower 48 states, recorded in Montana, and rated by the USDA to survive −25 °F or colder — the bottom of zone 4b. Each links to its USDA PLANTS profile.

Trees 23

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 87

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 229

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 155

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 Boyes, MT.

Soil in Boyes, MT

The soil mapped at the center of ZIP 59316 is Arvada — silt loam, moderately well drained.

TextureSilt loama good balance for most vegetables
pH7.2neutral; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter2%moderate
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Arvada-Bone complex, 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 59316; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Boyes, MT

Summer high91 °Faverage high, July
Winter low11 °Faverage low, January
Hot days45days a year at 90 °F or more
Freezing nights172nights a year at 32 °F or less
Growing degree days2,783base 50 °F — the season’s usable heat
Longest day15 h 40 mindaylight on June 21
Shortest day8 h 43 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation16.1 inper year, rain and melted snow

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 37 °F, low 11 °F 37°11° JanFebruary: average high 40 °F, low 14 °F 40°14° FebMarch: average high 52 °F, low 24 °F 52°24° MarApril: average high 61 °F, low 33 °F 61°33° AprMay: average high 71 °F, low 42 °F 71°42° MayJune: average high 81 °F, low 52 °F 81°52° JunJuly: average high 91 °F, low 59 °F 91°59° JulAugust: average high 90 °F, low 56 °F 90°56° AugSeptember: average high 79 °F, low 46 °F 79°46° SepOctober: average high 63 °F, low 34 °F 63°34° OctNovember: average high 48 °F, low 22 °F 48°22° NovDecember: average high 38 °F, low 14 °F 38°14° Dec

Precipitation by month inches

0″1″2″3″January: 0.52 in precipitation 0.5 JanFebruary: 0.52 in precipitation 0.5 FebMarch: 0.93 in precipitation 0.9 MarApril: 1.90 in precipitation 1.9 AprMay: 2.89 in precipitation 2.9 MayJune: 2.47 in precipitation 2.5 JunJuly: 2.03 in precipitation 2.0 JulAugust: 1.33 in precipitation 1.3 AugSeptember: 1.28 in precipitation 1.3 SepOctober: 1.24 in precipitation 1.2 OctNovember: 0.50 in precipitation 0.5 NovDecember: 0.46 in precipitation 0.5 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Broadus, MT (17 mi away); precipitation: Boyes 1.7 Nne, MT (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 4b.

593324b
Hammond, MT · 18 mi
593174b
Broadus, MT · 22 mi
593144b
Biddle, MT · 26 mi
593434b
Olive, MT · 28 mi
593114b
Alzada, MT · 28 mi
593454b
Powderville, MT · 36 mi
593244b
Ekalaka, MT · 38 mi
827314b
Weston, WY · 38 mi

Montana planting zones →

Questions about 59316

What planting zone is ZIP code 59316?

ZIP code 59316 (Boyes, MT) is in USDA hardiness zone 4b on the 2023 map: the coldest night of an average winter reaches −25 to −20 °F (−31.7 to −28.9 °C).

When is the last frost in Boyes, MT?

The median last spring frost (32 °F) near 59316 is May 16; after May 29 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Broadus station.

When is the first frost in Boyes, MT?

The median first fall frost near 59316 is September 28, giving a median frost-free growing season of 135 days.

When should I plant tomatoes in 59316?

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 59316 get?

About 16.1 inches of precipitation a year (NOAA 1991–2020 normals, Boyes 1.7 Nne station).

How hot do summers get in Boyes, MT?

The average high peaks at 91 °F in July, with about 45 days a year at 90 °F or more.

What kind of soil does 59316 have?

The USDA soil survey maps Arvada at the center of ZIP 59316: silt loam, moderately well drained, pH about 7.2 (neutral).

Did spring come early in Boyes, MT in 2026?

Spring leaf-out near 59316 came on Mar 23 in 2026, 18 days earlier than the 1991–2020 average (Apr 10), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Boyes, MT?

Long-day onions: the longest day near 59316 is 15 h 40 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 59316 change?

Yes. The 2012 USDA map put 59316 in zone 4a; the 2023 map puts it in zone 4b. The newer map uses 1991–2020 data and more weather stations.