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

Planting zone for 58646 — Mott, ND

ZIP code 58646 (Mott, Hettinger County) is in USDA zone 4a: the coldest winter night averages −30 to −25 °F. The median last spring frost is May 16 and the first fall frost September 25.

Where ZIP 58646 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.

Zone4a−30 to −25 °F
Coldest night−34.4 to −31.7 °C
Last frostMay 16
First frostSep 25
2012 zone4a

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 4a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Mott, ND…

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 Mott, ND

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 25median — 10% chance by Sep 11
Growing season129 daysfrost-free, median

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

From the NOAA station Mott, ND — 2 miles away, elevation 2,425 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 58646

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 31 – Aug 14
GarlicPlant cloves · Sep 11 – Oct 16
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 16) and first fall frost (Sep 25) 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 58646 came on Apr 8 — 10 days earlier than the 1991–2020 average (Apr 18).

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 4a in North Dakota

342 plants native to the lower 48 states, recorded in North Dakota, and rated by the USDA to survive −30 °F or colder — the bottom of zone 4a. Each links to its USDA PLANTS profile.

Trees 21

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °Fbalsam poplar80 ft · blooms late spring · high shade tolerance · to −79 °Fbigtooth aspen65 ft · blooms mid spring · high shade tolerance · to −43 °Fblack ash65 ft · blooms early spring · high shade tolerance · to −47 °Fblack locust60 ft · blooms spring · high shade tolerance · to −37 °F

Shrubs 56

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican plum24 ft · blooms mid spring · high shade tolerance · to −38 °Fbeaked hazelnut15 ft · blooms early spring · low shade tolerance · to −47 °Fbig sagebrush4 ft · blooms mid summer · high shade tolerance · to −43 °F

Wildflowers & perennials 146

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine sweetvetch2 ft · blooms early summer · high shade tolerance · to −62 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °FAmerican speedwell0.8 ft · blooms mid summer · low shade tolerance · to −38 °F

Grasses 110

alkali cordgrass3 ft · blooms late summer · high shade tolerance · to −38 °Falkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °Fanalogue sedge1.5 ft · blooms late spring · medium shade tolerance · to −38 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °FBebb's sedge3 ft · blooms late spring · low shade tolerance · to −38 °F

Vines 4

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fdevil's darning needles15 ft · blooms mid summer · medium 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 Mott, ND.

Soil in Mott, ND

The soil mapped at the center of ZIP 58646 is Regan — silt loam, poorly drained.

TextureSilt loama good balance for most vegetables
pH7.9alkaline; most vegetables like 6.0–7.0
DrainagePoorly drainedconsider raised beds
Organic matter4%moderate
Hydrologic groupB/Dmoderate when drained; wet otherwise
Farmland classNot prime farmlandUSDA classification

Map unit: Regan silt loam, saline, 0 to 2 percent slopes, occasionally flooded.

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 58646; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Mott, ND

Summer high85 °Faverage high, July
Winter low4 °Faverage low, January
Hot days30days a year at 90 °F or more
Freezing nights196nights a year at 32 °F or less
Growing degree days2,189base 50 °F — the season’s usable heat
Longest day15 h 49 mindaylight on June 21
Shortest day8 h 35 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation17.2 inper year, rain and melted snow

Average high and low, by month

−10°0°10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 27 °F, low 4 °F 27°4° JanFebruary: average high 31 °F, low 7 °F 31°7° FebMarch: average high 43 °F, low 17 °F 43°17° MarApril: average high 56 °F, low 28 °F 56°28° AprMay: average high 67 °F, low 40 °F 67°40° MayJune: average high 77 °F, low 50 °F 77°50° JunJuly: average high 85 °F, low 55 °F 85°55° JulAugust: average high 85 °F, low 53 °F 85°53° AugSeptember: average high 75 °F, low 43 °F 75°43° SepOctober: average high 58 °F, low 31 °F 58°31° OctNovember: average high 42 °F, low 18 °F 42°18° NovDecember: average high 31 °F, low 8 °F 31°8° Dec

Precipitation by month inches

0″1″2″3″January: 0.45 in precipitation 0.5 JanFebruary: 0.78 in precipitation 0.8 FebMarch: 0.74 in precipitation 0.7 MarApril: 1.53 in precipitation 1.5 AprMay: 2.47 in precipitation 2.5 MayJune: 2.68 in precipitation 2.7 JunJuly: 2.78 in precipitation 2.8 JulAugust: 1.64 in precipitation 1.6 AugSeptember: 1.65 in precipitation 1.6 SepOctober: 1.41 in precipitation 1.4 OctNovember: 0.46 in precipitation 0.5 NovDecember: 0.61 in precipitation 0.6 Dec

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

Nearby ZIP codes

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

585624a
New Leipzig, ND · 13 mi
586504a
Regent, ND · 16 mi
586414b
Lefor, ND · 21 mi
585334a
Elgin, ND · 23 mi
586394b
Hettinger, ND · 28 mi
586474b
New England, ND · 32 mi
586494b
Reeder, ND · 34 mi
586524a
Richardton, ND · 35 mi

North Dakota planting zones →

Questions about 58646

What planting zone is ZIP code 58646?

ZIP code 58646 (Mott, ND) is in USDA hardiness zone 4a on the 2023 map: the coldest night of an average winter reaches −30 to −25 °F (−34.4 to −31.7 °C).

When is the last frost in Mott, ND?

The median last spring frost (32 °F) near 58646 is May 16; after May 30 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Mott station.

When is the first frost in Mott, ND?

The median first fall frost near 58646 is September 25, giving a median frost-free growing season of 129 days.

When should I plant tomatoes in 58646?

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 58646 get?

About 17.2 inches of precipitation a year (NOAA 1991–2020 normals, Mott station).

How hot do summers get in Mott, ND?

The average high peaks at 85 °F in July, with about 30 days a year at 90 °F or more.

What kind of soil does 58646 have?

The USDA soil survey maps Regan at the center of ZIP 58646: silt loam, poorly drained, pH about 7.9 (alkaline).

Did spring come early in Mott, ND in 2026?

Spring leaf-out near 58646 came on Apr 8 in 2026, 10 days earlier than the 1991–2020 average (Apr 18), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Mott, ND?

Long-day onions: the longest day near 58646 is 15 h 49 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).