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

Planting zone for 56639 — Effie, MN

ZIP code 56639 (Effie, 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 56639 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 Effie, 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 Effie, 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 — 20 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 56639

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 56639 came on Apr 25 — about the same time as the 1991–2020 average (Apr 27).

average
Apr 272026
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).

Soil in Effie, MN

The soil mapped at the center of ZIP 56639 is Rifle — mucky peat, very poorly drained.

TextureMucky peattop layer

DrainageVery poorly drainedconsider raised beds

Organic matter85%high

Hydrologic groupA/Ddrains fast once dried out; wet otherwise

Farmland classNot prime farmlandUSDA classification

Map unit: Rifle-Rifle, ponded, complex, 0 to 1 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 56639; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Effie, 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 02 mindaylight on June 21

Shortest day8 h 23 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

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Marcell 5ne, MN (20 mi away); precipitation: Marcell 5ne, MN (20 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 3b.

Nett Lake, MN · 24 mi

Littlefork, MN · 25 mi

566803b

Spring Lake, MN · 26 mi

Minnesota planting zones →

Questions about 56639

What planting zone is ZIP code 56639?

ZIP code 56639 (Effie, 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 Effie, MN?

The median last spring frost (32 °F) near 56639 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 Effie, MN?

The median first fall frost near 56639 is October 2, giving a median frost-free growing season of 140 days.

When should I plant tomatoes in 56639?

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 56639 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 Effie, 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 56639 have?

The USDA soil survey maps Rifle at the center of ZIP 56639: mucky peat, very poorly drained.

Did spring come early in Effie, MN in 2026?

Spring leaf-out near 56639 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 Effie, MN?

Long-day onions: the longest day near 56639 is 16 h 02 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).