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

Planting zone for 55745 — Grand Rapids, MN

ZIP code 55745 (Grand Rapids, Itasca County) is in USDA zone 4a: the coldest winter night averages −30 to −25 °F. The median last spring frost is May 17 and the first fall frost September 24.

Where ZIP 55745 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 17
First frostSep 24
2012 zone3b

Was 3b on the 2012 map — half a zone warmer now. 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 Rapids, 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 Grand Rapids, MN

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 17median — 50% chance of a later frost
Safe for tender plantsMay 31only 10% chance of frost after
First fall frostSeptember 24median — 10% chance by Sep 10
Growing season130 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 6 and returns around October 5.

From the NOAA station Grand Rpds Forest Lab, MN — 2 miles away, elevation 1,309 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 55745

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 5 – Apr 19
SpinachSow outdoors · Apr 5 – Apr 26
Broccoli, cabbageStart indoors · Mar 8 – Mar 22
Broccoli, cabbageTransplant · Apr 26 – May 10
Onion setsPlant outdoors · Apr 19 – May 3
PotatoesPlant outdoors · Apr 26 – May 10
LettuceSow outdoors · Apr 19 – May 3
Carrots, beetsSow outdoors · Apr 26 – May 10
TomatoesStart indoors · Mar 22 – Apr 5
TomatoesTransplant · May 24 – Jun 7
Peppers, eggplantStart indoors · Mar 8 – Mar 22
Peppers, eggplantTransplant · May 31 – Jun 14
BeansSow outdoors · May 24 – Jun 7
Sweet cornSow outdoors · May 24 – Jun 7
Cucumbers, squashSow outdoors · May 24 – Jun 7
Fall lettuce, spinachSow outdoors · Jul 30 – Aug 13
GarlicPlant cloves · Sep 10 – Oct 15
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 17) and first fall frost (Sep 24) 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 55745 came on Apr 22 — 3 days earlier than the 1991–2020 average (Apr 25).

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 Minnesota

445 plants native to the lower 48 states, recorded in Minnesota, and rated by the USDA to survive −30 °F or colder — the bottom of zone 4a. Each links to its USDA PLANTS profile.

Trees 45

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 °Farborvitae50 ft · blooms mid spring · medium shade tolerance · to −33 °Fbalsam fir60 ft · blooms mid summer · low shade tolerance · to −43 °Fbalsam poplar80 ft · blooms late spring · high shade tolerance · to −79 °F

Shrubs 77

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny 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 hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican hornbeam30 ft · blooms mid spring · low shade tolerance · to −34 °F

Wildflowers & perennials 173

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °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 lotus3 ft · blooms mid summer · high shade tolerance · to −36 °F

Grasses 140

alkali cordgrass3 ft · blooms late summer · high 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 °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 °F

Vines 3

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 °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 Rapids, MN.

Soil in Grand Rapids, MN

The soil mapped at the center of ZIP 55745 is Udorthents — loam, well drained.

TextureLoama good balance for most vegetables
pH7.8slightly alkaline; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter0.75%low — add compost
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Udorthents, nearly level to rolling.

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 55745; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Grand Rapids, MN

Summer high80 °Faverage high, July
Winter low−1 °Faverage low, January
Hot days6days a year at 90 °F or more
Freezing nights187nights a year at 32 °F or less
Growing degree days1,866base 50 °F — the season’s usable heat
Longest day15 h 56 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)
Precipitation29.4 inper year, rain and melted snow
Snowfall60 inper year; 129 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 19 °F, low -1 °F 19°−1° JanFebruary: average high 26 °F, low 2 °F 26°2° FebMarch: average high 39 °F, low 15 °F 39°15° MarApril: average high 53 °F, low 28 °F 53°28° AprMay: average high 66 °F, low 40 °F 66°40° MayJune: average high 75 °F, low 51 °F 75°51° JunJuly: average high 80 °F, low 55 °F 80°55° JulAugust: average high 78 °F, low 53 °F 78°53° AugSeptember: average high 68 °F, low 45 °F 68°45° SepOctober: average high 53 °F, low 33 °F 53°33° OctNovember: average high 36 °F, low 20 °F 36°20° NovDecember: average high 23 °F, low 7 °F 23°7° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″January: 0.97 in precipitation, 12.2 in snowfall 1.0❄12 JanFebruary: 0.85 in precipitation, 9.7 in snowfall 0.8❄10 FebMarch: 1.33 in precipitation, 7.5 in snowfall 1.3❄8 MarApril: 2.10 in precipitation, 5.6 in snowfall 2.1❄6 AprMay: 3.23 in precipitation, 0.2 in snowfall 3.2 MayJune: 4.70 in precipitation 4.7 JunJuly: 4.14 in precipitation 4.1 JulAugust: 3.40 in precipitation 3.4 AugSeptember: 3.05 in precipitation 3.0 SepOctober: 2.79 in precipitation, 2 in snowfall 2.8❄2 OctNovember: 1.59 in precipitation, 9 in snowfall 1.6❄9 NovDecember: 1.23 in precipitation, 13.4 in snowfall 1.2❄13 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Grand Rpds Forest Lab, MN (2 mi away); precipitation: Grand Rpds Forest Lab, MN (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

1 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

557304a
Grand Rapids, MN · <1 mi
557444a
Grand Rapids, MN · <1 mi
557224a
Coleraine, MN · 6 mi
557214a
Cohasset, MN · 7 mi
557864a
Taconite, MN · 9 mi
557644a
Marble, MN · 13 mi
557093b
Bovey, MN · 14 mi
557164a
Calumet, MN · 14 mi

All 3 ZIP codes in Grand Rapids → · Minnesota planting zones →

Questions about 55745

What planting zone is ZIP code 55745?

ZIP code 55745 (Grand Rapids, MN) 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 Rapids, MN?

The median last spring frost (32 °F) near 55745 is May 17; after May 31 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Grand Rpds Forest Lab station.

When is the first frost in Grand Rapids, MN?

The median first fall frost near 55745 is September 24, giving a median frost-free growing season of 130 days.

When should I plant tomatoes in 55745?

Start tomato seeds indoors around Mar 22 – Apr 5 and set transplants outside around May 24 – Jun 7, one to three weeks after the median last frost.

How much rain and snow does 55745 get?

About 29.4 inches of precipitation a year and 60 inches of snowfall (NOAA 1991–2020 normals, Grand Rpds Forest Lab station).

How hot do summers get in Grand Rapids, MN?

The average high peaks at 80 °F in July, with about 6 days a year at 90 °F or more.

What kind of soil does 55745 have?

The USDA soil survey maps Udorthents at the center of ZIP 55745: loam, well drained, pH about 7.8 (slightly alkaline).

Did spring come early in Grand Rapids, MN in 2026?

Spring leaf-out near 55745 came on Apr 22 in 2026, 3 days earlier than the 1991–2020 average (Apr 25), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Grand Rapids, MN?

Long-day onions: the longest day near 55745 is 15 h 56 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 55745 change?

Yes. The 2012 USDA map put 55745 in zone 3b; the 2023 map puts it in zone 4a. The newer map uses 1991–2020 data and more weather stations.