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

Planting zone for 56628 — Bigfork, MN

ZIP code 56628 (Bigfork, Itasca County) is in USDA zone 3b: the coldest winter night averages −35 to −30 °F. The median last spring frost is May 14 and the first fall frost October 2.

Where ZIP 56628 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.

Zone3b−35 to −30 °F
Coldest night−37.2 to −34.4 °C
Last frostMay 14
First frostOct 2
2012 zone3b

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 3b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Bigfork, MN…

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 Bigfork, MN

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 14median — 50% chance of a later frost
Safe for tender plantsMay 30only 10% chance of frost after
First fall frostOctober 2median — 10% chance by Sep 20
Growing season140 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 3 and returns around October 14.

From the NOAA station Marcell 5ne, MN — 7 miles away, elevation 1,388 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 56628

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 2 – Apr 16
SpinachSow outdoors · Apr 2 – Apr 23
Broccoli, cabbageStart indoors · Mar 5 – Mar 19
Broccoli, cabbageTransplant · Apr 23 – May 7
Onion setsPlant outdoors · Apr 16 – Apr 30
PotatoesPlant outdoors · Apr 23 – May 7
LettuceSow outdoors · Apr 16 – Apr 30
Carrots, beetsSow outdoors · Apr 23 – May 7
TomatoesStart indoors · Mar 19 – Apr 2
TomatoesTransplant · May 21 – Jun 4
Peppers, eggplantStart indoors · Mar 5 – Mar 19
Peppers, eggplantTransplant · May 28 – Jun 11
BeansSow outdoors · May 21 – Jun 4
Sweet cornSow outdoors · May 21 – Jun 4
Cucumbers, squashSow outdoors · May 21 – Jun 4
Fall lettuce, spinachSow outdoors · Aug 7 – Aug 21
GarlicPlant cloves · Sep 18 – Oct 23
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 14) and first fall frost (Oct 2) 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 56628 came on Apr 25 — about the same time as the 1991–2020 average (Apr 27).

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 3b in Minnesota

287 plants native to the lower 48 states, recorded in Minnesota, and rated by the USDA to survive −35 °F or colder — the bottom of zone 3b. Each links to its USDA PLANTS profile.

Trees 33

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °Fbalsam fir60 ft · blooms mid summer · low shade tolerance · to −43 °Fbalsam poplar80 ft · blooms late spring · high shade tolerance · to −79 °Fbigtooth aspen65 ft · blooms mid spring · high shade tolerance · to −43 °F

Shrubs 50

Allegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Falternateleaf dogwood25 ft · blooms mid spring · low shade tolerance · to −47 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican mountain ash40 ft · blooms early summer · medium shade tolerance · to −38 °FAmerican plum24 ft · blooms mid spring · high shade tolerance · to −38 °Fbeaked hazelnut15 ft · blooms early spring · low shade tolerance · to −47 °F

Wildflowers & perennials 102

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °FAmerican speedwell0.8 ft · blooms mid summer · low shade tolerance · to −38 °FAmerican vetch1.3 ft · blooms late spring · high shade tolerance · to −38 °F

Grasses 93

alkali cordgrass3 ft · blooms late summer · high shade tolerance · to −38 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °Fbasin wildrye5 ft · blooms early spring · high shade tolerance · to −43 °Fbeaked sedge4 ft · blooms late spring · low shade tolerance · to −38 °FBebb's sedge3 ft · blooms late spring · low shade tolerance · to −38 °FBicknell's sedge3 ft · blooms late spring · low shade tolerance · to −38 °F

Vines 2

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fdevil's darning needles15 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 Bigfork, MN.

Soil in Bigfork, MN

The soil mapped at the center of ZIP 56628 is Seelyeville — muck, very poorly drained.

TextureMucktop layer
DrainageVery poorly drainedconsider raised beds
Organic matter65%high
Hydrologic groupA/Ddrains fast once dried out; wet otherwise
Farmland classNot prime farmlandUSDA classification

Map unit: Seelyeville-Bowstring association.

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 56628; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Bigfork, MN

Summer high77 °Faverage high, July
Winter low−5 °Faverage low, January
Hot days1days a year at 90 °F or more
Freezing nights192nights a year at 32 °F or less
Growing degree days1,736base 50 °F — the season’s usable heat
Longest day16 h 00 mindaylight on June 21
Shortest day8 h 25 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation31.1 inper year, rain and melted snow
Snowfall64 inper year; 137 days with snow on the ground

Average high and low, by month

−20°−10°0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 16 °F, low -5 °F 16°−5° JanFebruary: average high 22 °F, low -3 °F 22°−3° FebMarch: average high 36 °F, low 12 °F 36°12° MarApril: average high 49 °F, low 27 °F 49°27° AprMay: average high 63 °F, low 40 °F 63°40° MayJune: average high 72 °F, low 52 °F 72°52° JunJuly: average high 77 °F, low 56 °F 77°56° JulAugust: average high 75 °F, low 55 °F 75°55° AugSeptember: average high 66 °F, low 47 °F 66°47° SepOctober: average high 51 °F, low 35 °F 51°35° OctNovember: average high 34 °F, low 20 °F 34°20° NovDecember: average high 21 °F, low 5 °F 21°5° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″6″January: 0.91 in precipitation, 14.1 in snowfall 0.9❄14 JanFebruary: 0.77 in precipitation, 10 in snowfall 0.8❄10 FebMarch: 1.32 in precipitation, 7.7 in snowfall 1.3❄8 MarApril: 2.20 in precipitation, 5.2 in snowfall 2.2❄5 AprMay: 3.15 in precipitation, 0.2 in snowfall 3.1 MayJune: 4.21 in precipitation 4.2 JunJuly: 5.90 in precipitation 5.9 JulAugust: 3.46 in precipitation 3.5 AugSeptember: 3.71 in precipitation 3.7 SepOctober: 2.66 in precipitation, 1.2 in snowfall 2.7❄1 OctNovember: 1.57 in precipitation, 12.9 in snowfall 1.6❄13 NovDecember: 1.26 in precipitation, 12.8 in snowfall 1.3❄13 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Marcell 5ne, MN (7 mi away); precipitation: Marcell 5ne, MN (7 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 3b.

566573b
Marcell, MN · 10 mi
566393b
Effie, MN · 15 mi
566373b
Talmoon, MN · 16 mi
566883b
Wirt, MN · 16 mi
566313b
Bowstring, MN · 16 mi
566803b
Spring Lake, MN · 20 mi
557093b
Bovey, MN · 22 mi
566363b
Deer River, MN · 26 mi

Minnesota planting zones →

Questions about 56628

What planting zone is ZIP code 56628?

ZIP code 56628 (Bigfork, MN) is in USDA hardiness zone 3b on the 2023 map: the coldest night of an average winter reaches −35 to −30 °F (−37.2 to −34.4 °C).

When is the last frost in Bigfork, MN?

The median last spring frost (32 °F) near 56628 is May 14; after May 30 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Marcell 5ne station.

When is the first frost in Bigfork, MN?

The median first fall frost near 56628 is October 2, giving a median frost-free growing season of 140 days.

When should I plant tomatoes in 56628?

Start tomato seeds indoors around Mar 19 – Apr 2 and set transplants outside around May 21 – Jun 4, one to three weeks after the median last frost.

How much rain and snow does 56628 get?

About 31.1 inches of precipitation a year and 64 inches of snowfall (NOAA 1991–2020 normals, Marcell 5ne station).

How hot do summers get in Bigfork, MN?

The average high peaks at 77 °F in July, with about 1 days a year at 90 °F or more.

What kind of soil does 56628 have?

The USDA soil survey maps Seelyeville at the center of ZIP 56628: muck, very poorly drained.

Did spring come early in Bigfork, MN in 2026?

Spring leaf-out near 56628 came on Apr 25 in 2026, about the same as the 1991–2020 average (Apr 27), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Bigfork, MN?

Long-day onions: the longest day near 56628 is 16 h 00 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).