Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 55787 — Tamarack, MN

ZIP code 55787 (Tamarack, Aitkin County) is in USDA zone 4a: the coldest winter night averages −30 to −25 °F. The median last spring frost is May 31 and the first fall frost September 18.

Where ZIP 55787 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 31

First frostSep 18

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 Tamarack, 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 Tamarack, MN

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostMay 31median — 50% chance of a later frost

Safe for tender plantsJune 20only 10% chance of frost after

First fall frostSeptember 18median — 10% chance by Sep 1

Growing season107 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 17 and returns around September 28.

From the NOAA station Wright 3 E, MN — 8 miles away, elevation 1,329 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 55787

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 19 – May 3

SpinachSow outdoors · Apr 19 – May 10

Broccoli, cabbageStart indoors · Mar 22 – Apr 5

Broccoli, cabbageTransplant · May 10 – May 24

Onion setsPlant outdoors · May 3 – May 17

PotatoesPlant outdoors · May 10 – May 24

LettuceSow outdoors · May 3 – May 17

Carrots, beetsSow outdoors · May 10 – May 24

TomatoesStart indoors · Apr 5 – Apr 19

TomatoesTransplant · Jun 7 – Jun 21

Peppers, eggplantStart indoors · Mar 22 – Apr 5

Peppers, eggplantTransplant · Jun 14 – Jun 28

BeansSow outdoors · Jun 7 – Jun 21

Sweet cornSow outdoors · Jun 7 – Jun 21

Cucumbers, squashSow outdoors · Jun 7 – Jun 21

Fall lettuce, spinachSow outdoors · Jul 24 – Aug 7

GarlicPlant cloves · Sep 4 – Oct 9

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 31) and first fall frost (Sep 18) 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 55787 came on Apr 22 — 4 days earlier than the 1991–2020 average (Apr 26).

average
Apr 262026
Apr 22

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).

Soil in Tamarack, MN

The soil mapped at the center of ZIP 55787 is Sandwick — loamy sand, poorly drained.

TextureLoamy sanddrains and warms fast; dries out and needs more feeding

pH5.8moderately acidic; most vegetables like 6.0–7.0

DrainagePoorly drainedconsider raised beds

Organic matter1.25%low — add compost

Hydrologic groupC/Dslow when drained; wet otherwise

Farmland classNot prime farmlandUSDA classification

Map unit: Sandwick loamy sand.

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 55787; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Tamarack, MN

Summer high76 °Faverage high, July

Winter low−3 °Faverage low, January

Hot days1days a year at 90 °F or more

Freezing nights190nights a year at 32 °F or less

Growing degree days1,457base 50 °F — the season’s usable heat

Longest day15 h 51 mindaylight on June 21

Shortest day8 h 33 mindaylight on December 21

Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)

Precipitation31.2 inper year, rain and melted snow

Snowfall59 inper year; 121 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Wright 3 E, MN (8 mi away); precipitation: Wright 3 E, MN (8 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 4a.

Kettle River, MN · 16 mi

557524a

Jacobson, MN · 17 mi

557364a

Floodwood, MN · 19 mi

557834a

Sturgeon Lake, MN · 23 mi

557674a

Moose Lake, MN · 25 mi

Minnesota planting zones →

Questions about 55787

What planting zone is ZIP code 55787?

ZIP code 55787 (Tamarack, 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 Tamarack, MN?

The median last spring frost (32 °F) near 55787 is May 31; after June 20 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Wright 3 E station.

When is the first frost in Tamarack, MN?

The median first fall frost near 55787 is September 18, giving a median frost-free growing season of 107 days.

When should I plant tomatoes in 55787?

Start tomato seeds indoors around Apr 5 – Apr 19 and set transplants outside around Jun 7 – Jun 21, one to three weeks after the median last frost.

How much rain and snow does 55787 get?

About 31.2 inches of precipitation a year and 59 inches of snowfall (NOAA 1991–2020 normals, Wright 3 E station).

How hot do summers get in Tamarack, MN?

The average high peaks at 76 °F in July, with about 1 days a year at 90 °F or more.

What kind of soil does 55787 have?

The USDA soil survey maps Sandwick at the center of ZIP 55787: loamy sand, poorly drained, pH about 5.8 (moderately acidic).

Did spring come early in Tamarack, MN in 2026?

Spring leaf-out near 55787 came on Apr 22 in 2026, 4 days earlier than the 1991–2020 average (Apr 26), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Tamarack, MN?

Long-day onions: the longest day near 55787 is 15 h 51 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 55787 change?

Yes. The 2012 USDA map put 55787 in zone 3b; the 2023 map puts it in zone 4a. The newer map uses 1991–2020 data and more weather stations.