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

Planting zone for 55702 — Alborn, MN

ZIP code 55702 (Alborn, St. Louis County) is in USDA zone 4a: the coldest winter night averages −30 to −25 °F. The median last spring frost is May 29 and the first fall frost September 18.

Where ZIP 55702 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 29

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 Alborn, 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 Alborn, MN

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 29median — 50% chance of a later frost

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

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

Growing season111 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 16 and returns around September 29.

From the NOAA station Floodwood 3 Ne, MN — 11 miles away, elevation 1,260 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 55702

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 17 – May 1

SpinachSow outdoors · Apr 17 – May 8

Broccoli, cabbageStart indoors · Mar 20 – Apr 3

Broccoli, cabbageTransplant · May 8 – May 22

Onion setsPlant outdoors · May 1 – May 15

PotatoesPlant outdoors · May 8 – May 22

LettuceSow outdoors · May 1 – May 15

Carrots, beetsSow outdoors · May 8 – May 22

TomatoesStart indoors · Apr 3 – Apr 17

TomatoesTransplant · Jun 5 – Jun 19

Peppers, eggplantStart indoors · Mar 20 – Apr 3

Peppers, eggplantTransplant · Jun 12 – Jun 26

BeansSow outdoors · Jun 5 – Jun 19

Sweet cornSow outdoors · Jun 5 – Jun 19

Cucumbers, squashSow outdoors · Jun 5 – Jun 19

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 29) 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 55702 came on Apr 30 — 4 days later than the 1991–2020 average (Apr 26).

average
Apr 262026
Apr 30

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 4a in Minnesota

445 plants native to the lower 48 states, recorded in Minnesota, and rated by the USDA to survive −30 °F or colder — the bottom of zone 4a. 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 Alborn, MN.

Soil in Alborn, MN

The soil mapped at the center of ZIP 55702 is Culver — silt loam, moderately well drained.

TextureSilt loama good balance for most vegetables

pH5.5moderately acidic; most vegetables like 6.0–7.0

DrainageModerately well drainednatural drainage class

Organic matter5%high

Hydrologic groupC/Dslow when drained; wet otherwise

Farmland classprime farmlandUSDA classification

Map unit: Culver-Dusler-Ellsburg complex, 0 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 55702; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Alborn, MN

Summer high77 °Faverage high, July

Winter low−4 °Faverage low, January

Hot days1days a year at 90 °F or more

Freezing nights200nights a year at 32 °F or less

Growing degree days1,587base 50 °F — the season’s usable heat

Longest day15 h 53 mindaylight on June 21

Shortest day8 h 31 mindaylight on December 21

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

Precipitation28.1 inper year, rain and melted snow

Snowfall56 inper year; 124 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: Floodwood 3 Ne, MN (11 mi away); precipitation: Floodwood 3 Ne, MN (11 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

2 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

557794a

Saginaw, MN · 10 mi

557114a

Brookston, MN · 10 mi

557653b

Meadowlands, MN · 11 mi

557364a

Floodwood, MN · 13 mi

Minnesota planting zones →

Questions about 55702

What planting zone is ZIP code 55702?

ZIP code 55702 (Alborn, 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 Alborn, MN?

The median last spring frost (32 °F) near 55702 is May 29; after June 13 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Floodwood 3 Ne station.

When is the first frost in Alborn, MN?

The median first fall frost near 55702 is September 18, giving a median frost-free growing season of 111 days.

When should I plant tomatoes in 55702?

Start tomato seeds indoors around Apr 3 – Apr 17 and set transplants outside around Jun 5 – Jun 19, one to three weeks after the median last frost.

How much rain and snow does 55702 get?

About 28.1 inches of precipitation a year and 56 inches of snowfall (NOAA 1991–2020 normals, Floodwood 3 Ne station).

How hot do summers get in Alborn, 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 55702 have?

The USDA soil survey maps Culver at the center of ZIP 55702: silt loam, moderately well drained, pH about 5.5 (moderately acidic).

Did spring come early in Alborn, MN in 2026?

Spring leaf-out near 55702 came on Apr 30 in 2026, 4 days later than the 1991–2020 average (Apr 26), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Alborn, MN?

Long-day onions: the longest day near 55702 is 15 h 53 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 55702 change?

Yes. The 2012 USDA map put 55702 in zone 3b; the 2023 map puts it in zone 4a. The newer map uses 1991–2020 data and more weather stations.