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

Planting zone for 55795 — Willow River, MN

ZIP code 55795 (Willow River, Pine County) is in USDA zone 4a: the coldest winter night averages −30 to −25 °F. The median last spring frost is May 12 and the first fall frost October 2.

Where ZIP 55795 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 12

First frostOct 2

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 Willow River, 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 Willow River, MN

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 12median — 50% chance of a later frost

Safe for tender plantsMay 26only 10% chance of frost after

First fall frostOctober 2median — 10% chance by Sep 20

Growing season144 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 30 and returns around October 14.

From the NOAA station Moose Lake 1 Sse, MN — 11 miles away, elevation 1,109 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 55795

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 31 – Apr 14

SpinachSow outdoors · Mar 31 – Apr 21

Broccoli, cabbageStart indoors · Mar 3 – Mar 17

Broccoli, cabbageTransplant · Apr 21 – May 5

Onion setsPlant outdoors · Apr 14 – Apr 28

PotatoesPlant outdoors · Apr 21 – May 5

LettuceSow outdoors · Apr 14 – Apr 28

Carrots, beetsSow outdoors · Apr 21 – May 5

TomatoesStart indoors · Mar 17 – Mar 31

TomatoesTransplant · May 19 – Jun 2

Peppers, eggplantStart indoors · Mar 3 – Mar 17

Peppers, eggplantTransplant · May 26 – Jun 9

BeansSow outdoors · May 19 – Jun 2

Sweet cornSow outdoors · May 19 – Jun 2

Cucumbers, squashSow outdoors · May 19 – Jun 2

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 12) 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 55795 came on Apr 21 — about the same time as the 1991–2020 average (Apr 23).

average
Apr 232026
Apr 21

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 Willow River, MN

The center of ZIP 55795 is mapped as No Digital Data Available: built-over ground without natural soil data. Garden soil here is usually imported or disturbed — test before you plant.

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 55795; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Willow River, MN

Summer high80 °Faverage high, July

Winter low1 °Faverage low, January

Hot days5days a year at 90 °F or more

Freezing nights175nights a year at 32 °F or less

Growing degree days2,012base 50 °F — the season’s usable heat

Longest day15 h 48 mindaylight on June 21

Shortest day8 h 36 mindaylight on December 21

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

Precipitation31.5 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Moose Lake 1 Sse, MN (11 mi away); precipitation: Moose Lake 1 Sse, MN (11 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 4a.

557834a

Sturgeon Lake, MN · 8 mi

Moose Lake, MN · 12 mi

557564a

Kerrick, MN · 14 mi

557574a

Kettle River, MN · 16 mi

Minnesota planting zones →

Questions about 55795

What planting zone is ZIP code 55795?

ZIP code 55795 (Willow River, 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 Willow River, MN?

The median last spring frost (32 °F) near 55795 is May 12; after May 26 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Moose Lake 1 Sse station.

When is the first frost in Willow River, MN?

The median first fall frost near 55795 is October 2, giving a median frost-free growing season of 144 days.

When should I plant tomatoes in 55795?

Start tomato seeds indoors around Mar 17 – Mar 31 and set transplants outside around May 19 – Jun 2, one to three weeks after the median last frost.

How much rain and snow does 55795 get?

About 31.5 inches of precipitation a year (NOAA 1991–2020 normals, Moose Lake 1 Sse station).

How hot do summers get in Willow River, MN?

The average high peaks at 80 °F in July, with about 5 days a year at 90 °F or more.

Did spring come early in Willow River, MN in 2026?

Spring leaf-out near 55795 came on Apr 21 in 2026, about the same as the 1991–2020 average (Apr 23), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Willow River, MN?

Long-day onions: the longest day near 55795 is 15 h 48 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 55795 change?

Yes. The 2012 USDA map put 55795 in zone 3b; the 2023 map puts it in zone 4a. The newer map uses 1991–2020 data and more weather stations.