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

Planting zone for Grand Forks Afb, ND

Grand Forks Afb, ND is in USDA zone 4a across its 2 ZIP codes. The median last spring frost is May 16 and the first fall frost September 27.

Grand Forks Afb on the zone map

Outlined: its 2 ZIP code areas · 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
ZIP codes2
Last frostMay 16
First frostSep 27
Growing season133 days

4a 2 ZIPs

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, 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 Grand Forks Afb

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

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 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.

ZIP codes in Grand Forks Afb

582044a
−30 to −25 °F
582054a
−30 to −25 °F

North Dakota planting zones →

Questions about Grand Forks Afb

What planting zone is Grand Forks Afb, ND?

Grand Forks Afb, ND is in USDA hardiness zone 4a on the 2023 map (4a: −30 to −25 °F).

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

The median last spring frost is May 16 and the median first fall frost is September 27 (NOAA 1991–2020 normals, Grand Forks Intl Airport station).

When can I plant a garden in Grand Forks Afb, ND?

Cool-season crops like peas and spinach go in around Apr 4 – Apr 25; tomatoes, peppers, beans and squash after about May 23, once frost risk has passed.

What kind of onions grow in Grand Forks Afb, ND?

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

How much rain and snow does Grand Forks Afb, ND get?

About 21.7 inches of precipitation a year and 48 inches of snowfall (NOAA 1991–2020 normals).