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

Planting zone for 58730 — Crosby, ND

ZIP code 58730 (Crosby, Divide County) is in USDA zone 4a: the coldest winter night averages −30 to −25 °F. The median last spring frost is May 17 and the first fall frost September 23.

Where ZIP 58730 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 17

First frostSep 23

2012 zone3b

Was 3b 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 4a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Crosby, 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 Crosby, ND

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 17median — 50% chance of a later frost

Safe for tender plantsMay 28only 10% chance of frost after

First fall frostSeptember 23median — 10% chance by Sep 11

Growing season128 daysfrost-free, median

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

From the NOAA station Crosby, ND — 4 miles away, elevation 1,959 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 58730

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 5 – Apr 19

SpinachSow outdoors · Apr 5 – Apr 26

Broccoli, cabbageStart indoors · Mar 8 – Mar 22

Broccoli, cabbageTransplant · Apr 26 – May 10

Onion setsPlant outdoors · Apr 19 – May 3

PotatoesPlant outdoors · Apr 26 – May 10

LettuceSow outdoors · Apr 19 – May 3

Carrots, beetsSow outdoors · Apr 26 – May 10

TomatoesStart indoors · Mar 22 – Apr 5

TomatoesTransplant · May 24 – Jun 7

Peppers, eggplantStart indoors · Mar 8 – Mar 22

Peppers, eggplantTransplant · May 31 – Jun 14

BeansSow outdoors · May 24 – Jun 7

Sweet cornSow outdoors · May 24 – Jun 7

Cucumbers, squashSow outdoors · May 24 – Jun 7

Fall lettuce, spinachSow outdoors · Jul 29 – Aug 12

GarlicPlant cloves · Sep 9 – Oct 14

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 17) and first fall frost (Sep 23) 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 58730 came on Apr 24 — about the same time as the 1991–2020 average (Apr 24).

average
Apr 242026
Apr 24

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.

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 Crosby, ND.

Soil in Crosby, ND

The soil mapped at the center of ZIP 58730 is Noonan — loam, moderately well drained.

TextureLoama good balance for most vegetables

pH6.5neutral; most vegetables like 6.0–7.0

DrainageModerately well drainednatural drainage class

Organic matter4%moderate

Hydrologic groupCwater soaks in slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Noonan-Niobell loams, 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 58730; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Crosby, ND

Summer high81 °Faverage high, July

Winter low0 °Faverage low, January

Hot days11days a year at 90 °F or more

Freezing nights186nights a year at 32 °F or less

Growing degree days1,959base 50 °F — the season’s usable heat

Longest day16 h 11 mindaylight on June 21

Shortest day8 h 15 mindaylight on December 21

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

Precipitation16.1 inper year, rain and melted snow

Snowfall41 inper year; 108 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Crosby, ND (4 mi away); precipitation: Crosby, ND (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

North Dakota planting zones →

Questions about 58730

What planting zone is ZIP code 58730?

ZIP code 58730 (Crosby, 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 Crosby, ND?

The median last spring frost (32 °F) near 58730 is May 17; after May 28 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Crosby station.

When is the first frost in Crosby, ND?

The median first fall frost near 58730 is September 23, giving a median frost-free growing season of 128 days.

When should I plant tomatoes in 58730?

Start tomato seeds indoors around Mar 22 – Apr 5 and set transplants outside around May 24 – Jun 7, one to three weeks after the median last frost.

How much rain and snow does 58730 get?

About 16.1 inches of precipitation a year and 41 inches of snowfall (NOAA 1991–2020 normals, Crosby station).

How hot do summers get in Crosby, ND?

The average high peaks at 81 °F in July, with about 11 days a year at 90 °F or more.

What kind of soil does 58730 have?

The USDA soil survey maps Noonan at the center of ZIP 58730: loam, moderately well drained, pH about 6.5 (neutral).

Did spring come early in Crosby, ND in 2026?

Spring leaf-out near 58730 came on Apr 24 in 2026, about the same as the 1991–2020 average (Apr 24), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Crosby, ND?

Long-day onions: the longest day near 58730 is 16 h 11 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 58730 change?

Yes. The 2012 USDA map put 58730 in zone 3b; the 2023 map puts it in zone 4a. The newer map uses 1991–2020 data and more weather stations.