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

Planting zone for 58577 — Washburn, ND

ZIP code 58577 (Washburn, McLean County) is in USDA zone 4a: the coldest winter night averages −30 to −25 °F. The median last spring frost is May 12 and the first fall frost September 30.

Where ZIP 58577 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 12
First frostSep 30
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 Washburn, 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 Washburn, ND

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 12median — 50% chance of a later frost
Safe for tender plantsMay 25only 10% chance of frost after
First fall frostSeptember 30median — 10% chance by Sep 18
Growing season140 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 3 and returns around October 8.

From the NOAA station Washburn, ND — 2 miles away, elevation 1,755 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 58577

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 31 – Apr 14
SpinachSow outdoors · Mar 31 – Apr 21
Broccoli, cabbageStart indoors · Mar 3 – Mar 17
Broccoli, cabbageTransplant · Apr 21 – May 5
Onion setsPlant outdoors · Apr 14 – Apr 28
PotatoesPlant outdoors · Apr 21 – May 5
LettuceSow outdoors · Apr 14 – Apr 28
Carrots, beetsSow outdoors · Apr 21 – May 5
TomatoesStart indoors · Mar 17 – Mar 31
TomatoesTransplant · May 19 – Jun 2
Peppers, eggplantStart indoors · Mar 3 – Mar 17
Peppers, eggplantTransplant · May 26 – Jun 9
BeansSow outdoors · May 19 – Jun 2
Sweet cornSow outdoors · May 19 – Jun 2
Cucumbers, squashSow outdoors · May 19 – Jun 2
Fall lettuce, spinachSow outdoors · Aug 5 – Aug 19
GarlicPlant cloves · Sep 16 – Oct 21
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 12) and first fall frost (Sep 30) 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 58577 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 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

Shrubs 56

Wildflowers & perennials 146

Grasses 110

Vines 4

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 Washburn, ND.

Soil in Washburn, ND

The soil mapped at the center of ZIP 58577 is Williams — loam, well drained.

TextureLoama good balance for most vegetables
pH7.2neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter4%moderate
Hydrologic groupBwater soaks in moderately
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Williams-Bowbells loams, 3 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 58577; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Washburn, ND

Summer high83 °Faverage high, July
Winter low2 °Faverage low, January
Hot days17days a year at 90 °F or more
Freezing nights182nights a year at 32 °F or less
Growing degree days2,229base 50 °F — the season’s usable heat
Longest day15 h 57 mindaylight on June 21
Shortest day8 h 28 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation17.7 inper year, rain and melted snow
Snowfall43 inper year

Average high and low, by month

−10°0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 22 °F, low 2 °F 22°2° JanFebruary: average high 27 °F, low 5 °F 27°5° FebMarch: average high 40 °F, low 18 °F 40°18° MarApril: average high 55 °F, low 30 °F 55°30° AprMay: average high 67 °F, low 42 °F 67°42° MayJune: average high 76 °F, low 52 °F 76°52° JunJuly: average high 83 °F, low 57 °F 83°57° JulAugust: average high 83 °F, low 55 °F 83°55° AugSeptember: average high 73 °F, low 46 °F 73°46° SepOctober: average high 57 °F, low 32 °F 57°32° OctNovember: average high 40 °F, low 19 °F 40°19° NovDecember: average high 27 °F, low 9 °F 27°9° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″January: 0.39 in precipitation, 7.2 in snowfall 0.4❄7 JanFebruary: 0.47 in precipitation, 6.4 in snowfall 0.5❄6 FebMarch: 0.56 in precipitation, 6.9 in snowfall 0.6❄7 MarApril: 1.49 in precipitation, 4.1 in snowfall 1.5❄4 AprMay: 2.82 in precipitation, 0.9 in snowfall 2.8❄1 MayJune: 3.24 in precipitation 3.2 JunJuly: 2.49 in precipitation 2.5 JulAugust: 2.20 in precipitation 2.2 AugSeptember: 1.46 in precipitation 1.5 SepOctober: 1.41 in precipitation, 2.4 in snowfall 1.4❄2 OctNovember: 0.69 in precipitation, 6.6 in snowfall 0.7❄7 NovDecember: 0.45 in precipitation, 8.6 in snowfall 0.5❄9 Dec

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

Nearby ZIP codes

All 8 nearest ZIP codes share zone 4a.

North Dakota planting zones →

Questions about 58577

What planting zone is ZIP code 58577?

ZIP code 58577 (Washburn, 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 Washburn, ND?

The median last spring frost (32 °F) near 58577 is May 12; after May 25 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Washburn station.

When is the first frost in Washburn, ND?

The median first fall frost near 58577 is September 30, giving a median frost-free growing season of 140 days.

When should I plant tomatoes in 58577?

Start tomato seeds indoors around Mar 17 – Mar 31 and set transplants outside around May 19 – Jun 2, one to three weeks after the median last frost.

How much rain and snow does 58577 get?

About 17.7 inches of precipitation a year and 43 inches of snowfall (NOAA 1991–2020 normals, Washburn station).

How hot do summers get in Washburn, ND?

The average high peaks at 83 °F in July, with about 17 days a year at 90 °F or more.

What kind of soil does 58577 have?

The USDA soil survey maps Williams at the center of ZIP 58577: loam, well drained, pH about 7.2 (neutral).

Did spring come early in Washburn, ND in 2026?

Spring leaf-out near 58577 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 Washburn, ND?

Long-day onions: the longest day near 58577 is 15 h 57 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).