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

Planting zone for 59219 — Dagmar, MT

ZIP code 59219 (Dagmar, Sheridan County) is in USDA zone 3b: the coldest winter night averages −35 to −30 °F. The median last spring frost is May 16 and the first fall frost September 18.

Where ZIP 59219 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.

Zone3b−35 to −30 °F
Coldest night−37.2 to −34.4 °C
Last frostMay 16
First frostSep 18
2012 zone3b

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 3b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Dagmar, 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 Dagmar, 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 30only 10% chance of frost after
First fall frostSeptember 18median — 10% chance by Sep 7
Growing season125 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 5 and returns around September 25.

From the NOAA station Medicine Lake 3 Se, MT — 15 miles away, elevation 1,942 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 59219

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 · Jul 24 – Aug 7
GarlicPlant cloves · Sep 4 – Oct 9
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 16) and first fall frost (Sep 18) 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 59219 came on Apr 21 — about the same time as the 1991–2020 average (Apr 20).

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 3b in Montana

304 plants native to the lower 48 states, recorded in Montana, and rated by the USDA to survive −35 °F or colder — the bottom of zone 3b. Each links to its USDA PLANTS profile.

Trees 17

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 °Feastern cottonwood190 ft · blooms spring · high shade tolerance · to −43 °FEngelmann spruce120 ft · blooms late spring · low shade tolerance · to −50 °F

Shrubs 60

alderleaf mountain mahogany15 ft · blooms late spring · medium shade tolerance · to −41 °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 °FBarclay's willow15 ft · high shade tolerance · to −43 °Fbeaked hazelnut15 ft · blooms early spring · low shade tolerance · to −47 °F

Wildflowers & perennials 109

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 bistort1.5 ft · blooms mid spring · high shade tolerance · to −38 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °F

Grasses 109

alkali cordgrass3 ft · blooms late summer · high shade tolerance · to −38 °Falkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °Falpine timothy1.4 ft · blooms late spring · medium shade tolerance · to −43 °Fanalogue sedge1.5 ft · blooms late spring · medium shade tolerance · to −38 °Farctic bluegrass2 ft · high shade tolerance · to −62 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °F

Vines 2

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °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 Dagmar, MT.

Soil in Dagmar, MT

The soil mapped at the center of ZIP 59219 is Manning — coarse sandy loam, somewhat excessively drained.

TextureCoarse sandy loamdrains and warms fast; dries out and needs more feeding
pH7.0neutral; most vegetables like 6.0–7.0
DrainageSomewhat excessively drainednatural drainage class
Organic matter3.5%moderate
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Manning coarse sandy loam, 0 to 6 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 59219; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Dagmar, MT

Summer high83 °Faverage high, July
Winter low0 °Faverage low, January
Hot days18days a year at 90 °F or more
Freezing nights192nights a year at 32 °F or less
Growing degree days2,037base 50 °F — the season’s usable heat
Longest day16 h 08 mindaylight on June 21
Shortest day8 h 17 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation14.1 inper year, rain and melted snow

Average high and low, by month

−10°0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 22 °F, low 0 °F 22°0° JanFebruary: average high 26 °F, low 4 °F 26°4° FebMarch: average high 39 °F, low 16 °F 39°16° MarApril: average high 55 °F, low 30 °F 55°30° AprMay: average high 67 °F, low 41 °F 67°41° MayJune: average high 75 °F, low 51 °F 75°51° JunJuly: average high 83 °F, low 56 °F 83°56° JulAugust: average high 83 °F, low 53 °F 83°53° AugSeptember: average high 72 °F, low 42 °F 72°42° SepOctober: average high 55 °F, low 29 °F 55°29° OctNovember: average high 38 °F, low 16 °F 38°16° NovDecember: average high 27 °F, low 5 °F 27°5° Dec

Precipitation by month inches

0″1″2″3″January: 0.33 in precipitation 0.3 JanFebruary: 0.16 in precipitation 0.2 FebMarch: 0.42 in precipitation 0.4 MarApril: 0.93 in precipitation 0.9 AprMay: 2.39 in precipitation 2.4 MayJune: 2.90 in precipitation 2.9 JunJuly: 2.65 in precipitation 2.6 JulAugust: 1.54 in precipitation 1.5 AugSeptember: 1.17 in precipitation 1.2 SepOctober: 0.89 in precipitation 0.9 OctNovember: 0.36 in precipitation 0.4 NovDecember: 0.32 in precipitation 0.3 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Medicine Lake 3 Se, MT (15 mi away); precipitation: Medicine Lake 3 Se, MT (15 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.

588453b
Grenora, ND · 12 mi
592113b
Antelope, MT · 12 mi
592423b
Homestead, MT · 17 mi
592473b
Medicine Lake, MT · 17 mi
588564a
Zahl, ND · 19 mi
592753b
Westby, MT · 21 mi
592583b
Reserve, MT · 23 mi
592264a
Froid, MT · 23 mi

Montana planting zones →

Questions about 59219

What planting zone is ZIP code 59219?

ZIP code 59219 (Dagmar, MT) is in USDA hardiness zone 3b on the 2023 map: the coldest night of an average winter reaches −35 to −30 °F (−37.2 to −34.4 °C).

When is the last frost in Dagmar, MT?

The median last spring frost (32 °F) near 59219 is May 16; after May 30 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Medicine Lake 3 Se station.

When is the first frost in Dagmar, MT?

The median first fall frost near 59219 is September 18, giving a median frost-free growing season of 125 days.

When should I plant tomatoes in 59219?

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 59219 get?

About 14.1 inches of precipitation a year (NOAA 1991–2020 normals, Medicine Lake 3 Se station).

How hot do summers get in Dagmar, MT?

The average high peaks at 83 °F in July, with about 18 days a year at 90 °F or more.

What kind of soil does 59219 have?

The USDA soil survey maps Manning at the center of ZIP 59219: coarse sandy loam, somewhat excessively drained, pH about 7.0 (neutral).

Did spring come early in Dagmar, MT in 2026?

Spring leaf-out near 59219 came on Apr 21 in 2026, about the same as the 1991–2020 average (Apr 20), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Dagmar, MT?

Long-day onions: the longest day near 59219 is 16 h 08 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).