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

Planting zone for 55781 — Side Lake, MN

ZIP code 55781 (Side Lake, St. Louis County) is in USDA zone 3b: the coldest winter night averages −35 to −30 °F. The median last spring frost is June 1 and the first fall frost September 15.

Where ZIP 55781 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 frostJun 1

First frostSep 15

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 Side Lake, 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 Side Lake, MN

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostJune 1median — 50% chance of a later frost

Safe for tender plantsJune 18only 10% chance of frost after

First fall frostSeptember 15median — 10% chance by Aug 27

Growing season104 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 20 and returns around September 27.

From the NOAA station Celina 2e, MN — 13 miles away, elevation 1,286 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 55781

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 20 – May 4

SpinachSow outdoors · Apr 20 – May 11

Broccoli, cabbageStart indoors · Mar 23 – Apr 6

Broccoli, cabbageTransplant · May 11 – May 25

Onion setsPlant outdoors · May 4 – May 18

PotatoesPlant outdoors · May 11 – May 25

LettuceSow outdoors · May 4 – May 18

Carrots, beetsSow outdoors · May 11 – May 25

TomatoesStart indoors · Apr 6 – Apr 20

TomatoesTransplant · Jun 8 – Jun 22

Peppers, eggplantStart indoors · Mar 23 – Apr 6

Peppers, eggplantTransplant · Jun 15 – Jun 29

BeansSow outdoors · Jun 8 – Jun 22

Sweet cornSow outdoors · Jun 8 – Jun 22

Cucumbers, squashSow outdoors · Jun 8 – Jun 22

Fall lettuce, spinachSow outdoors · Jul 21 – Aug 4

GarlicPlant cloves · Sep 1 – Oct 6

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jun 1) and first fall frost (Sep 15) 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 55781 came on Apr 25 — 3 days earlier than the 1991–2020 average (Apr 28).

average
Apr 282026
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 3b in Minnesota

287 plants native to the lower 48 states, recorded in Minnesota, and rated by the USDA to survive −35 °F or colder — the bottom of zone 3b. 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 Side Lake, MN.

Soil in Side Lake, MN

The soil mapped at the center of ZIP 55781 is Eagleview — loamy sand, somewhat excessively drained.

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

pH6.5neutral; most vegetables like 6.0–7.0

DrainageSomewhat excessively drainednatural drainage class

Organic matter2%moderate

Hydrologic groupAwater soaks in fast

Farmland classNot prime farmlandUSDA classification

Map unit: Eagleview and Menahga soils, 1 to 8 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 55781; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Side Lake, MN

Summer high77 °Faverage high, July

Winter low−7 °Faverage low, January

Hot days1days a year at 90 °F or more

Freezing nights212nights a year at 32 °F or less

Growing degree days1,416base 50 °F — the season’s usable heat

Longest day16 h 00 mindaylight on June 21

Shortest day8 h 25 mindaylight on December 21

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

Precipitation28.5 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: Celina 2e, MN (13 mi away); precipitation: Chisholm 0.4 Wsw, MN (16 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.

Minnesota planting zones →

Questions about 55781

What planting zone is ZIP code 55781?

ZIP code 55781 (Side Lake, 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 Side Lake, MN?

The median last spring frost (32 °F) near 55781 is June 1; after June 18 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Celina 2e station.

When is the first frost in Side Lake, MN?

The median first fall frost near 55781 is September 15, giving a median frost-free growing season of 104 days.

When should I plant tomatoes in 55781?

Start tomato seeds indoors around Apr 6 – Apr 20 and set transplants outside around Jun 8 – Jun 22, one to three weeks after the median last frost.

How much rain and snow does 55781 get?

About 28.5 inches of precipitation a year (NOAA 1991–2020 normals, Chisholm 0.4 Wsw station).

How hot do summers get in Side Lake, 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 55781 have?

The USDA soil survey maps Eagleview at the center of ZIP 55781: loamy sand, somewhat excessively drained, pH about 6.5 (neutral).

Did spring come early in Side Lake, MN in 2026?

Spring leaf-out near 55781 came on Apr 25 in 2026, 3 days earlier than the 1991–2020 average (Apr 28), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Side Lake, MN?

Long-day onions: the longest day near 55781 is 16 h 00 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).