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

Planting zone for 59050 — Lodge Grass, MT

ZIP code 59050 (Lodge Grass, Big Horn County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 21 and the first fall frost September 17.

Where ZIP 59050 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 21

First frostSep 17

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 Lodge Grass, 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 Lodge Grass, MT

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 21median — 50% chance of a later frost

Safe for tender plantsJune 2only 10% chance of frost after

First fall frostSeptember 17median — 10% chance by Sep 5

Growing season117 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 10 and returns around September 28.

From the NOAA station Wyola 1 Sw, MT — 10 miles away, elevation 3,730 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 59050

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 9 – Apr 23

SpinachSow outdoors · Apr 9 – Apr 30

Broccoli, cabbageStart indoors · Mar 12 – Mar 26

Broccoli, cabbageTransplant · Apr 30 – May 14

Onion setsPlant outdoors · Apr 23 – May 7

PotatoesPlant outdoors · Apr 30 – May 14

LettuceSow outdoors · Apr 23 – May 7

Carrots, beetsSow outdoors · Apr 30 – May 14

TomatoesStart indoors · Mar 26 – Apr 9

TomatoesTransplant · May 28 – Jun 11

Peppers, eggplantStart indoors · Mar 12 – Mar 26

Peppers, eggplantTransplant · Jun 4 – Jun 18

BeansSow outdoors · May 28 – Jun 11

Sweet cornSow outdoors · May 28 – Jun 11

Cucumbers, squashSow outdoors · May 28 – Jun 11

Fall lettuce, spinachSow outdoors · Jul 23 – Aug 6

GarlicPlant cloves · Sep 3 – Oct 8

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 21) and first fall frost (Sep 17) 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 59050 came on Mar 21 — 18 days earlier than the 1991–2020 average (Apr 8).

average
Apr 82026
Mar 21

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 Lodge Grass, MT.

Soil in Lodge Grass, MT

The soil mapped at the center of ZIP 59050 is Alluvial land — loam, somewhat poorly drained.

TextureLoama good balance for most vegetables

pH7.9alkaline; most vegetables like 6.0–7.0

DrainageSomewhat poorly drainedconsider raised beds

Organic matter3.5%moderate

Hydrologic groupCwater soaks in slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Alluvial land, wet.

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 59050; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Lodge Grass, MT

Summer high90 °Faverage high, July

Winter low10 °Faverage low, January

Hot days39days a year at 90 °F or more

Freezing nights197nights a year at 32 °F or less

Growing degree days2,222base 50 °F — the season’s usable heat

Longest day15 h 39 mindaylight on June 21

Shortest day8 h 44 mindaylight on December 21

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

Precipitation16.5 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: Wyola 1 Sw, MT (10 mi away); precipitation: Wyola 1 Sw, MT (10 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

590894b

Wyola, MT · 14 mi

590314b

Garryowen, MT · 17 mi

590755a

Saint Xavier, MT · 21 mi

590355a

Fort Smith, MT · 23 mi

828385a

Parkman, WY · 24 mi

590224b

Crow Agency, MT · 24 mi

828395a

Ranchester, WY · 25 mi

590165a

Busby, MT · 29 mi

Montana planting zones →

Questions about 59050

What planting zone is ZIP code 59050?

ZIP code 59050 (Lodge Grass, 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 Lodge Grass, MT?

The median last spring frost (32 °F) near 59050 is May 21; after June 2 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Wyola 1 Sw station.

When is the first frost in Lodge Grass, MT?

The median first fall frost near 59050 is September 17, giving a median frost-free growing season of 117 days.

When should I plant tomatoes in 59050?

Start tomato seeds indoors around Mar 26 – Apr 9 and set transplants outside around May 28 – Jun 11, one to three weeks after the median last frost.

How much rain and snow does 59050 get?

About 16.5 inches of precipitation a year (NOAA 1991–2020 normals, Wyola 1 Sw station).

How hot do summers get in Lodge Grass, MT?

The average high peaks at 90 °F in July, with about 39 days a year at 90 °F or more.

What kind of soil does 59050 have?

The USDA soil survey maps Alluvial land at the center of ZIP 59050: loam, somewhat poorly drained, pH about 7.9 (alkaline).

Did spring come early in Lodge Grass, MT in 2026?

Spring leaf-out near 59050 came on Mar 21 in 2026, 18 days earlier than the 1991–2020 average (Apr 8), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Lodge Grass, MT?

Long-day onions: the longest day near 59050 is 15 h 39 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 59050 change?

Yes. The 2012 USDA map put 59050 in zone 4b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.