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

Planting zone for 59102 — Billings, MT

ZIP code 59102 (Billings, Yellowstone County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 5 and the first fall frost October 3.

Where ZIP 59102 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 5
First frostOct 3
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 Billings, 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 Billings, MT

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 5median — 50% chance of a later frost
Safe for tender plantsMay 21only 10% chance of frost after
First fall frostOctober 3median — 10% chance by Sep 20
Growing season149 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 23 and returns around October 14.

From the NOAA station Billings WFO, MT — 2 miles away, elevation 3,186 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 59102

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 24 – Apr 7
SpinachSow outdoors · Mar 24 – Apr 14
Broccoli, cabbageStart indoors · Feb 24 – Mar 10
Broccoli, cabbageTransplant · Apr 14 – Apr 28
Onion setsPlant outdoors · Apr 7 – Apr 21
PotatoesPlant outdoors · Apr 14 – Apr 28
LettuceSow outdoors · Apr 7 – Apr 21
Carrots, beetsSow outdoors · Apr 14 – Apr 28
TomatoesStart indoors · Mar 10 – Mar 24
TomatoesTransplant · May 12 – May 26
Peppers, eggplantStart indoors · Feb 24 – Mar 10
Peppers, eggplantTransplant · May 19 – Jun 2
BeansSow outdoors · May 12 – May 26
Sweet cornSow outdoors · May 12 – May 26
Cucumbers, squashSow outdoors · May 12 – May 26
Fall lettuce, spinachSow outdoors · Aug 8 – Aug 22
GarlicPlant cloves · Sep 19 – Oct 24
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 5) and first fall frost (Oct 3) 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 59102 came on Mar 2 — 30 days earlier than the 1991–2020 average (Apr 1).

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.

Trees 26

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 96

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 253

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 161

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 Billings, MT.

Soil in Billings, MT

The soil mapped at the center of ZIP 59102 is Keiser — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH7.0neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1%low — add compost
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Keiser silty clay loam, 0 to 1 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 59102; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Billings, MT

Summer high89 °Faverage high, July
Winter low15 °Faverage low, January
Hot days41days a year at 90 °F or more
Freezing nights158nights a year at 32 °F or less
Growing degree days2,534base 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)
Precipitation14.8 inper year, rain and melted snow
Snowfall48 inper year; 53 days with snow on the ground

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 37 °F, low 15 °F 37°15° JanFebruary: average high 41 °F, low 18 °F 41°18° FebMarch: average high 51 °F, low 25 °F 51°25° MarApril: average high 59 °F, low 34 °F 59°34° AprMay: average high 69 °F, low 43 °F 69°43° MayJune: average high 79 °F, low 51 °F 79°51° JunJuly: average high 89 °F, low 57 °F 89°57° JulAugust: average high 87 °F, low 55 °F 87°55° AugSeptember: average high 76 °F, low 46 °F 76°46° SepOctober: average high 61 °F, low 35 °F 61°35° OctNovember: average high 47 °F, low 24 °F 47°24° NovDecember: average high 37 °F, low 17 °F 37°17° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″January: 0.58 in precipitation, 9.2 in snowfall 0.6❄9 JanFebruary: 0.60 in precipitation, 9.6 in snowfall 0.6❄10 FebMarch: 1.02 in precipitation, 7.2 in snowfall 1.0❄7 MarApril: 1.80 in precipitation, 3.7 in snowfall 1.8❄4 AprMay: 2.45 in precipitation, 0.4 in snowfall 2.5 MayJune: 2.09 in precipitation 2.1 JunJuly: 1.37 in precipitation 1.4 JulAugust: 0.80 in precipitation 0.8 AugSeptember: 1.40 in precipitation, 0.3 in snowfall 1.4 SepOctober: 1.47 in precipitation, 3.5 in snowfall 1.5❄4 OctNovember: 0.63 in precipitation, 5.6 in snowfall 0.6❄6 NovDecember: 0.61 in precipitation, 8.7 in snowfall 0.6❄9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Billings WFO, MT (2 mi away); precipitation: Billings WFO, MT (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5a.

591035a
Billings, MT · 4 mi
591045a
Billings, MT · 4 mi
591085a
Billings, MT · 4 mi
591115a
Billings, MT · 4 mi
591125a
Billings, MT · 4 mi
591145a
Billings, MT · 4 mi
591155a
Billings, MT · 4 mi
591165a
Billings, MT · 4 mi

All 14 ZIP codes in Billings → · Montana planting zones →

Questions about 59102

What planting zone is ZIP code 59102?

ZIP code 59102 (Billings, 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 Billings, MT?

The median last spring frost (32 °F) near 59102 is May 5; after May 21 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Billings WFO station.

When is the first frost in Billings, MT?

The median first fall frost near 59102 is October 3, giving a median frost-free growing season of 149 days.

When should I plant tomatoes in 59102?

Start tomato seeds indoors around Mar 10 – Mar 24 and set transplants outside around May 12 – May 26, one to three weeks after the median last frost.

How much rain and snow does 59102 get?

About 14.8 inches of precipitation a year and 48 inches of snowfall (NOAA 1991–2020 normals, Billings WFO station).

How hot do summers get in Billings, MT?

The average high peaks at 89 °F in July, with about 41 days a year at 90 °F or more.

What kind of soil does 59102 have?

The USDA soil survey maps Keiser at the center of ZIP 59102: silt loam, well drained, pH about 7.0 (neutral).

Did spring come early in Billings, MT in 2026?

Spring leaf-out near 59102 came on Mar 2 in 2026, 30 days earlier than the 1991–2020 average (Apr 1), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Billings, MT?

Long-day onions: the longest day near 59102 is 15 h 43 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 59102 change?

Yes. The 2012 USDA map put 59102 in zone 4b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.