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

Planting zone for 56201 — Willmar, MN

ZIP code 56201 (Willmar, Kandiyohi County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is April 30 and the first fall frost October 7.

Where ZIP 56201 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.

Zone4b−25 to −20 °F

Coldest night−31.7 to −28.9 °C

Last frostApr 30

First frostOct 7

2012 zone4b

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 4b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Willmar, 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 Willmar, MN

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 30median — 50% chance of a later frost

Safe for tender plantsMay 13only 10% chance of frost after

First fall frostOctober 7median — 10% chance by Sep 23

Growing season159 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 19 and returns around October 19.

From the NOAA station Willmar Wwtp, MN — within 1 mile, elevation 1,099 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 56201

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 19 – Apr 2

SpinachSow outdoors · Mar 19 – Apr 9

Broccoli, cabbageStart indoors · Feb 19 – Mar 5

Broccoli, cabbageTransplant · Apr 9 – Apr 23

Onion setsPlant outdoors · Apr 2 – Apr 16

PotatoesPlant outdoors · Apr 9 – Apr 23

LettuceSow outdoors · Apr 2 – Apr 16

Carrots, beetsSow outdoors · Apr 9 – Apr 23

TomatoesStart indoors · Mar 5 – Mar 19

TomatoesTransplant · May 7 – May 21

Peppers, eggplantStart indoors · Feb 19 – Mar 5

Peppers, eggplantTransplant · May 14 – May 28

BeansSow outdoors · May 7 – May 21

Sweet cornSow outdoors · May 7 – May 21

Cucumbers, squashSow outdoors · May 7 – May 21

Fall lettuce, spinachSow outdoors · Aug 12 – Aug 26

GarlicPlant cloves · Sep 23 – Oct 28

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 30) and first fall frost (Oct 7) 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 56201 came on Apr 17 — about the same time as the 1991–2020 average (Apr 19).

average
Apr 192026
Apr 17

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 4b in Minnesota

497 plants native to the lower 48 states, recorded in Minnesota, and rated by the USDA to survive −25 °F or colder — the bottom of zone 4b. Each links to its USDA PLANTS profile.

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 Willmar, MN.

Soil in Willmar, MN

The soil mapped at the center of ZIP 56201 is Udorthents — loam, well drained. Much of the area is built over (urban land); this is the natural soil underneath.

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: Urban land-Udorthents complex.

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 56201; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Willmar, MN

Summer high82 °Faverage high, July

Winter low3 °Faverage low, January

Hot days8days a year at 90 °F or more

Freezing nights166nights a year at 32 °F or less

Growing degree days2,547base 50 °F — the season’s usable heat

Longest day15 h 38 mindaylight on June 21

Shortest day8 h 45 mindaylight on December 21

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

Precipitation28.7 inper year, rain and melted snow

Snowfall46 inper year

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Willmar Wwtp, MN (within 1 mile); precipitation: Willmar Wwtp, MN (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 4b.

Prinsburg, MN · 12 mi

562534b

Lake Lillian, MN · 13 mi

Minnesota planting zones →

Questions about 56201

What planting zone is ZIP code 56201?

ZIP code 56201 (Willmar, MN) is in USDA hardiness zone 4b on the 2023 map: the coldest night of an average winter reaches −25 to −20 °F (−31.7 to −28.9 °C).

When is the last frost in Willmar, MN?

The median last spring frost (32 °F) near 56201 is April 30; after May 13 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Willmar Wwtp station.

When is the first frost in Willmar, MN?

The median first fall frost near 56201 is October 7, giving a median frost-free growing season of 159 days.

When should I plant tomatoes in 56201?

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

How much rain and snow does 56201 get?

About 28.7 inches of precipitation a year and 46 inches of snowfall (NOAA 1991–2020 normals, Willmar Wwtp station).

How hot do summers get in Willmar, MN?

The average high peaks at 82 °F in July, with about 8 days a year at 90 °F or more.

What kind of soil does 56201 have?

The USDA soil survey maps Udorthents at the center of ZIP 56201: loam, well drained, pH about 7.8 (slightly alkaline).

Did spring come early in Willmar, MN in 2026?

Spring leaf-out near 56201 came on Apr 17 in 2026, about the same as the 1991–2020 average (Apr 19), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Willmar, MN?

Long-day onions: the longest day near 56201 is 15 h 38 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).