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

Planting zone for 58121 — Fargo, ND

ZIP code 58121 (Fargo, Cass County) is in USDA zone 4a: the coldest winter night averages −30 to −25 °F. The median last spring frost is May 5 and the first fall frost October 3.

Where ZIP 58121 is

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 5
First frostOct 3
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 Fargo, 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 Fargo, ND

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 5median — 50% chance of a later frost
Safe for tender plantsMay 20only 10% chance of frost after
First fall frostOctober 3median — 10% chance by Sep 22
Growing season150 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 28 and returns around October 14.

From the NOAA station Moorhead, MN — 2 miles away, elevation 906 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 58121

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 24 – Apr 7
SpinachSow outdoors · Mar 24 – Apr 14
Broccoli, cabbageStart indoors · Feb 24 – Mar 10
Broccoli, cabbageTransplant · Apr 14 – Apr 28
Onion setsPlant outdoors · Apr 7 – Apr 21
PotatoesPlant outdoors · Apr 14 – Apr 28
LettuceSow outdoors · Apr 7 – Apr 21
Carrots, beetsSow outdoors · Apr 14 – Apr 28
TomatoesStart indoors · Mar 10 – Mar 24
TomatoesTransplant · May 12 – May 26
Peppers, eggplantStart indoors · Feb 24 – Mar 10
Peppers, eggplantTransplant · May 19 – Jun 2
BeansSow outdoors · May 12 – May 26
Sweet cornSow outdoors · May 12 – May 26
Cucumbers, squashSow outdoors · May 12 – May 26
Fall lettuce, spinachSow outdoors · Aug 8 – Aug 22
GarlicPlant cloves · Sep 19 – Oct 24
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 5) and first fall frost (Oct 3) 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 58121 came on Apr 23 — about the same time as the 1991–2020 average (Apr 21).

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 Fargo, ND.

Soil in Fargo, ND

The soil mapped at the center of ZIP 58121 is Aquerts — silty clay, poorly drained. Much of the area is built over (urban land); this is the natural soil underneath.

TextureSilty clayholds water and nutrients; slow to drain and warm up
pH7.2neutral; most vegetables like 6.0–7.0
DrainagePoorly drainedconsider raised beds
Organic matter5%high
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classNot prime farmlandUSDA classification

Map unit: Urban Land, 0 to 2 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 58121; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Fargo, ND

Summer high82 °Faverage high, July
Winter low0 °Faverage low, January
Hot days10days a year at 90 °F or more
Freezing nights170nights a year at 32 °F or less
Growing degree days2,453base 50 °F — the season’s usable heat
Longest day15 h 53 mindaylight on June 21
Shortest day8 h 31 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation24.7 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 17 °F, low 0 °F 17°0° JanFebruary: average high 23 °F, low 4 °F 23°4° FebMarch: average high 37 °F, low 18 °F 37°18° MarApril: average high 54 °F, low 32 °F 54°32° AprMay: average high 69 °F, low 45 °F 69°45° MayJune: average high 78 °F, low 56 °F 78°56° JunJuly: average high 82 °F, low 61 °F 82°61° JulAugust: average high 81 °F, low 59 °F 81°59° AugSeptember: average high 72 °F, low 49 °F 72°49° SepOctober: average high 55 °F, low 36 °F 55°36° OctNovember: average high 38 °F, low 21 °F 38°21° NovDecember: average high 23 °F, low 8 °F 23°8° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 0.68 in precipitation 0.7 JanFebruary: 0.65 in precipitation 0.7 FebMarch: 1.20 in precipitation 1.2 MarApril: 1.45 in precipitation 1.4 AprMay: 3.46 in precipitation 3.5 MayJune: 4.37 in precipitation 4.4 JunJuly: 3.42 in precipitation 3.4 JulAugust: 2.52 in precipitation 2.5 AugSeptember: 2.80 in precipitation 2.8 SepOctober: 2.42 in precipitation 2.4 OctNovember: 0.88 in precipitation 0.9 NovDecember: 0.83 in precipitation 0.8 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Moorhead, MN (2 mi away); precipitation: Fargo 1.2 Ese, ND (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 4a.

581064a
Fargo, ND · <1 mi
581074a
Fargo, ND · <1 mi
581084a
Fargo, ND · <1 mi
581224a
Fargo, ND · <1 mi
581244a
Fargo, ND · <1 mi
581254a
Fargo, ND · <1 mi
581264a
Fargo, ND · <1 mi
565614a
Moorhead, MN · <1 mi

All 13 ZIP codes in Fargo → · North Dakota planting zones →

Questions about 58121

What planting zone is ZIP code 58121?

ZIP code 58121 (Fargo, 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 Fargo, ND?

The median last spring frost (32 °F) near 58121 is May 5; after May 20 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Moorhead station.

When is the first frost in Fargo, ND?

The median first fall frost near 58121 is October 3, giving a median frost-free growing season of 150 days.

When should I plant tomatoes in 58121?

Start tomato seeds indoors around Mar 10 – Mar 24 and set transplants outside around May 12 – May 26, one to three weeks after the median last frost.

How much rain and snow does 58121 get?

About 24.7 inches of precipitation a year (NOAA 1991–2020 normals, Fargo 1.2 Ese station).

How hot do summers get in Fargo, ND?

The average high peaks at 82 °F in July, with about 10 days a year at 90 °F or more.

What kind of soil does 58121 have?

The USDA soil survey maps Aquerts at the center of ZIP 58121: silty clay, poorly drained, pH about 7.2 (neutral).

Did spring come early in Fargo, ND in 2026?

Spring leaf-out near 58121 came on Apr 23 in 2026, about the same as the 1991–2020 average (Apr 21), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Fargo, ND?

Long-day onions: the longest day near 58121 is 15 h 53 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).