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

Planting zone for 58204 — Grand Forks Afb, ND

ZIP code 58204 (Grand Forks Afb, Grand Forks 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 27.

Where ZIP 58204 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 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 Grand Forks Afb, 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 Grand Forks Afb, 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 31only 10% chance of frost after
First fall frostSeptember 27median — 10% chance by Sep 15
Growing season133 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 4 and returns around October 5.

From the NOAA station Grand Forks Intl Airport, ND — 9 miles away, elevation 843 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 58204

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 · 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 16) 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 58204 came on Apr 26 — about the same time as the 1991–2020 average (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.

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 Grand Forks Afb, ND.

Soil in Grand Forks Afb, ND

The soil mapped at the center of ZIP 58204 is Wyndmere — fine sandy loam, somewhat poorly drained.

TextureFine sandy loamdrains and warms fast; dries out and needs more feeding
pH7.5slightly alkaline; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter3%moderate
Hydrologic groupBwater soaks in moderately
Farmland classPrime farmland if drainedUSDA classification

Map unit: Wyndmere-Tiffany fine sandy loams, 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 58204; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Grand Forks Afb, ND

Summer high81 °Faverage high, July
Winter low−3 °Faverage low, January
Hot days9days a year at 90 °F or more
Freezing nights185nights a year at 32 °F or less
Growing degree days2,076base 50 °F — the season’s usable heat
Longest day16 h 02 mindaylight on June 21
Shortest day8 h 22 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation21.7 inper year, rain and melted snow
Snowfall48 inper year; 113 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 16 °F, low -3 °F 16°−3° JanFebruary: average high 21 °F, low 1 °F 21°1° FebMarch: average high 34 °F, low 15 °F 34°15° MarApril: average high 52 °F, low 29 °F 52°29° AprMay: average high 67 °F, low 41 °F 67°41° MayJune: average high 76 °F, low 53 °F 76°53° JunJuly: average high 81 °F, low 57 °F 81°57° JulAugust: average high 80 °F, low 54 °F 80°54° AugSeptember: average high 70 °F, low 45 °F 70°45° SepOctober: average high 54 °F, low 33 °F 54°33° OctNovember: average high 36 °F, low 18 °F 36°18° NovDecember: average high 21 °F, low 4 °F 21°4° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″January: 0.49 in precipitation, 9.9 in snowfall 0.5❄10 JanFebruary: 0.51 in precipitation, 7.1 in snowfall 0.5❄7 FebMarch: 0.91 in precipitation, 7.4 in snowfall 0.9❄7 MarApril: 1.21 in precipitation, 3.5 in snowfall 1.2❄4 AprMay: 2.80 in precipitation 2.8 MayJune: 3.77 in precipitation 3.8 JunJuly: 3.52 in precipitation 3.5 JulAugust: 2.81 in precipitation 2.8 AugSeptember: 2.26 in precipitation 2.3 SepOctober: 1.88 in precipitation, 1.6 in snowfall 1.9❄2 OctNovember: 0.92 in precipitation, 6.6 in snowfall 0.9❄7 NovDecember: 0.66 in precipitation, 12.3 in snowfall 0.7❄12 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Grand Forks Intl Airport, ND (9 mi away); precipitation: Grand Forks Intl Airport, ND (9 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 4a.

All 2 ZIP codes in Grand Forks Afb → · North Dakota planting zones →

Questions about 58204

What planting zone is ZIP code 58204?

ZIP code 58204 (Grand Forks Afb, 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 Grand Forks Afb, ND?

The median last spring frost (32 °F) near 58204 is May 16; after May 31 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Grand Forks Intl Airport station.

When is the first frost in Grand Forks Afb, ND?

The median first fall frost near 58204 is September 27, giving a median frost-free growing season of 133 days.

When should I plant tomatoes in 58204?

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 58204 get?

About 21.7 inches of precipitation a year and 48 inches of snowfall (NOAA 1991–2020 normals, Grand Forks Intl Airport station).

How hot do summers get in Grand Forks Afb, ND?

The average high peaks at 81 °F in July, with about 9 days a year at 90 °F or more.

What kind of soil does 58204 have?

The USDA soil survey maps Wyndmere at the center of ZIP 58204: fine sandy loam, somewhat poorly drained, pH about 7.5 (slightly alkaline).

Did spring come early in Grand Forks Afb, ND in 2026?

Spring leaf-out near 58204 came on Apr 26 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 Grand Forks Afb, ND?

Long-day onions: the longest day near 58204 is 16 h 02 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).