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

Planting zone for 58831 — Alexander, ND

ZIP code 58831 (Alexander, McKenzie County) is in USDA zone 4a: the coldest winter night averages −30 to −25 °F. The median last spring frost is May 9 and the first fall frost September 27.

Where ZIP 58831 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 9
First frostSep 27
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 Alexander, 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 Alexander, ND

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 9median — 50% chance of a later frost
Safe for tender plantsMay 22only 10% chance of frost after
First fall frostSeptember 27median — 10% chance by Sep 15
Growing season139 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 30 and returns around October 7.

From the NOAA station Watford City, ND — 17 miles away, elevation 2,169 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 58831

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 28 – Apr 11
SpinachSow outdoors · Mar 28 – Apr 18
Broccoli, cabbageStart indoors · Feb 28 – Mar 14
Broccoli, cabbageTransplant · Apr 18 – May 2
Onion setsPlant outdoors · Apr 11 – Apr 25
PotatoesPlant outdoors · Apr 18 – May 2
LettuceSow outdoors · Apr 11 – Apr 25
Carrots, beetsSow outdoors · Apr 18 – May 2
TomatoesStart indoors · Mar 14 – Mar 28
TomatoesTransplant · May 16 – May 30
Peppers, eggplantStart indoors · Feb 28 – Mar 14
Peppers, eggplantTransplant · May 23 – Jun 6
BeansSow outdoors · May 16 – May 30
Sweet cornSow outdoors · May 16 – May 30
Cucumbers, squashSow outdoors · May 16 – May 30
Fall lettuce, spinachSow outdoors · Aug 2 – Aug 16
GarlicPlant cloves · Sep 13 – Oct 18
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 9) and first fall frost (Sep 27) 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 58831 came on Apr 20 — about the same time as 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 Alexander, ND.

Soil in Alexander, ND

The soil mapped at the center of ZIP 58831 is Zahl — loam, well drained.

TextureLoama good balance for most vegetables
pH7.2neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2%moderate
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Zahl-Cabba-Maschetah complex, 6 to 70 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 58831; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Alexander, ND

Summer high82 °Faverage high, July
Winter low5 °Faverage low, January
Hot days22days a year at 90 °F or more
Freezing nights194nights a year at 32 °F or less
Growing degree days2,147base 50 °F — the season’s usable heat
Longest day16 h 01 mindaylight on June 21
Shortest day8 h 23 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation15.7 inper year, rain and melted snow
Snowfall50 inper year; 99 days with snow on the ground

Average high and low, by month

−10°0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 22 °F, low 5 °F 22°5° JanFebruary: average high 26 °F, low 8 °F 26°8° FebMarch: average high 39 °F, low 19 °F 39°19° MarApril: average high 53 °F, low 31 °F 53°31° AprMay: average high 65 °F, low 42 °F 65°42° MayJune: average high 74 °F, low 53 °F 74°53° JunJuly: average high 82 °F, low 58 °F 82°58° JulAugust: average high 82 °F, low 55 °F 82°55° AugSeptember: average high 71 °F, low 45 °F 71°45° SepOctober: average high 55 °F, low 33 °F 55°33° OctNovember: average high 38 °F, low 20 °F 38°20° NovDecember: average high 26 °F, low 10 °F 26°10° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″January: 0.50 in precipitation, 9.5 in snowfall 0.5❄10 JanFebruary: 0.41 in precipitation, 8.2 in snowfall 0.4❄8 FebMarch: 0.63 in precipitation, 7.3 in snowfall 0.6❄7 MarApril: 0.96 in precipitation, 4.2 in snowfall 1.0❄4 AprMay: 2.38 in precipitation, 1.4 in snowfall 2.4❄1 MayJune: 3.44 in precipitation 3.4 JunJuly: 2.63 in precipitation 2.6 JulAugust: 1.35 in precipitation 1.4 AugSeptember: 1.16 in precipitation 1.2 SepOctober: 1.04 in precipitation, 2.9 in snowfall 1.0❄3 OctNovember: 0.60 in precipitation, 6.8 in snowfall 0.6❄7 NovDecember: 0.55 in precipitation, 10.1 in snowfall 0.6❄10 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Watford City, ND (17 mi away); precipitation: Watford City, ND (17 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 4a.

588354a
Arnegard, ND · 12 mi
588384a
Cartwright, ND · 13 mi
588534a
Trenton, ND · 15 mi
588034a
Williston, ND · 20 mi
588024a
Williston, ND · 22 mi
588544a
Watford City, ND · 23 mi
592214a
Fairview, MT · 24 mi
592704a
Sidney, MT · 26 mi

North Dakota planting zones →

Questions about 58831

What planting zone is ZIP code 58831?

ZIP code 58831 (Alexander, 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 Alexander, ND?

The median last spring frost (32 °F) near 58831 is May 9; after May 22 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Watford City station.

When is the first frost in Alexander, ND?

The median first fall frost near 58831 is September 27, giving a median frost-free growing season of 139 days.

When should I plant tomatoes in 58831?

Start tomato seeds indoors around Mar 14 – Mar 28 and set transplants outside around May 16 – May 30, one to three weeks after the median last frost.

How much rain and snow does 58831 get?

About 15.7 inches of precipitation a year and 50 inches of snowfall (NOAA 1991–2020 normals, Watford City station).

How hot do summers get in Alexander, ND?

The average high peaks at 82 °F in July, with about 22 days a year at 90 °F or more.

What kind of soil does 58831 have?

The USDA soil survey maps Zahl at the center of ZIP 58831: loam, well drained, pH about 7.2 (neutral).

Did spring come early in Alexander, ND in 2026?

Spring leaf-out near 58831 came on Apr 20 in 2026, about the same as the 1991–2020 average (Apr 18), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Alexander, ND?

Long-day onions: the longest day near 58831 is 16 h 01 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).