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

Planting zone for 59105 — Billings, MT

ZIP code 59105 (Billings, Yellowstone County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 4 and the first fall frost October 7.

Where ZIP 59105 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 4
First frostOct 7
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 4median — 50% chance of a later frost
Safe for tender plantsMay 18only 10% chance of frost after
First fall frostOctober 7median — 10% chance by Sep 26
Growing season156 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 21 and returns around October 16.

From the NOAA station Billings Logan Intl Airport, MT — 6 miles away, elevation 3,583 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 59105

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 23 – Apr 6
SpinachSow outdoors · Mar 23 – Apr 13
Broccoli, cabbageStart indoors · Feb 23 – Mar 9
Broccoli, cabbageTransplant · Apr 13 – Apr 27
Onion setsPlant outdoors · Apr 6 – Apr 20
PotatoesPlant outdoors · Apr 13 – Apr 27
LettuceSow outdoors · Apr 6 – Apr 20
Carrots, beetsSow outdoors · Apr 13 – Apr 27
TomatoesStart indoors · Mar 9 – Mar 23
TomatoesTransplant · May 11 – May 25
Peppers, eggplantStart indoors · Feb 23 – Mar 9
Peppers, eggplantTransplant · May 18 – Jun 1
BeansSow outdoors · May 11 – May 25
Sweet cornSow outdoors · May 11 – May 25
Cucumbers, squashSow outdoors · May 11 – May 25
Fall lettuce, spinachSow outdoors · Aug 12 – Aug 26
GarlicPlant cloves · Sep 23 – Oct 28
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 4) and first fall frost (Oct 7) 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 59105 came on Mar 4 — 29 days earlier than the 1991–2020 average (Apr 2).

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 59105 is Cabbart — loam, well drained.

TextureLoama good balance for most vegetables
pH8.2alkaline; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.5%low — add compost
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Cabbart-Bonfri loams, 2 to 8 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 59105; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Billings, MT

Summer high87 °Faverage high, July
Winter low18 °Faverage low, January
Hot days32days a year at 90 °F or more
Freezing nights142nights a year at 32 °F or less
Growing degree days2,596base 50 °F — the season’s usable heat
Longest day15 h 44 mindaylight on June 21
Shortest day8 h 39 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation14.9 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 36 °F, low 18 °F 36°18° JanFebruary: average high 39 °F, low 20 °F 39°20° FebMarch: average high 49 °F, low 27 °F 49°27° MarApril: average high 57 °F, low 35 °F 57°35° AprMay: average high 67 °F, low 44 °F 67°44° MayJune: average high 77 °F, low 52 °F 77°52° JunJuly: average high 87 °F, low 59 °F 87°59° JulAugust: average high 86 °F, low 58 °F 86°58° AugSeptember: average high 74 °F, low 49 °F 74°49° SepOctober: average high 59 °F, low 37 °F 59°37° OctNovember: average high 46 °F, low 27 °F 46°27° NovDecember: average high 36 °F, low 19 °F 36°19° Dec

Precipitation by month inches

0″1″2″3″January: 0.53 in precipitation 0.5 JanFebruary: 0.54 in precipitation 0.5 FebMarch: 0.87 in precipitation 0.9 MarApril: 1.79 in precipitation 1.8 AprMay: 2.51 in precipitation 2.5 MayJune: 2.37 in precipitation 2.4 JunJuly: 1.33 in precipitation 1.3 JulAugust: 0.97 in precipitation 1.0 AugSeptember: 1.46 in precipitation 1.5 SepOctober: 1.44 in precipitation 1.4 OctNovember: 0.59 in precipitation 0.6 NovDecember: 0.52 in precipitation 0.5 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Billings Logan Intl Airport, MT (6 mi away); precipitation: Billings 4.5 Ne, MT (5 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5a.

591075a
Billings, MT · 7 mi
591035a
Billings, MT · 8 mi
591045a
Billings, MT · 8 mi
591085a
Billings, MT · 8 mi
591115a
Billings, MT · 8 mi
591125a
Billings, MT · 8 mi
591145a
Billings, MT · 8 mi
591155a
Billings, MT · 8 mi

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

Questions about 59105

What planting zone is ZIP code 59105?

ZIP code 59105 (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 59105 is May 4; after May 18 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Billings Logan Intl Airport station.

When is the first frost in Billings, MT?

The median first fall frost near 59105 is October 7, giving a median frost-free growing season of 156 days.

When should I plant tomatoes in 59105?

Start tomato seeds indoors around Mar 9 – Mar 23 and set transplants outside around May 11 – May 25, one to three weeks after the median last frost.

How much rain and snow does 59105 get?

About 14.9 inches of precipitation a year (NOAA 1991–2020 normals, Billings 4.5 Ne station).

How hot do summers get in Billings, MT?

The average high peaks at 87 °F in July, with about 32 days a year at 90 °F or more.

What kind of soil does 59105 have?

The USDA soil survey maps Cabbart at the center of ZIP 59105: loam, well drained, pH about 8.2 (alkaline).

Did spring come early in Billings, MT in 2026?

Spring leaf-out near 59105 came on Mar 4 in 2026, 29 days earlier than the 1991–2020 average (Apr 2), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Billings, MT?

Long-day onions: the longest day near 59105 is 15 h 44 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 59105 change?

Yes. The 2012 USDA map put 59105 in zone 4b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.