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

Planting zone for 55808 — Duluth, MN

ZIP code 55808 (Duluth, St. Louis County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is May 6 and the first fall frost October 9.

Where ZIP 55808 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 frostMay 6
First frostOct 9
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 Duluth, 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 Duluth, MN

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 6median — 50% chance of a later frost
Safe for tender plantsMay 25only 10% chance of frost after
First fall frostOctober 9median — 10% chance by Sep 24
Growing season154 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 24 and returns around October 24.

From the NOAA station Superior, WI — 9 miles away, elevation 607 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 55808

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 25 – Apr 8
SpinachSow outdoors · Mar 25 – Apr 15
Broccoli, cabbageStart indoors · Feb 25 – Mar 11
Broccoli, cabbageTransplant · Apr 15 – Apr 29
Onion setsPlant outdoors · Apr 8 – Apr 22
PotatoesPlant outdoors · Apr 15 – Apr 29
LettuceSow outdoors · Apr 8 – Apr 22
Carrots, beetsSow outdoors · Apr 15 – Apr 29
TomatoesStart indoors · Mar 11 – Mar 25
TomatoesTransplant · May 13 – May 27
Peppers, eggplantStart indoors · Feb 25 – Mar 11
Peppers, eggplantTransplant · May 20 – Jun 3
BeansSow outdoors · May 13 – May 27
Sweet cornSow outdoors · May 13 – May 27
Cucumbers, squashSow outdoors · May 13 – May 27
Fall lettuce, spinachSow outdoors · Aug 14 – Aug 28
GarlicPlant cloves · Sep 25 – Oct 30
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 6) and first fall frost (Oct 9) 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 55808 came on May 2 — 4 days later than the 1991–2020 average (Apr 28).

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.

Trees 47

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °Farborvitae50 ft · blooms mid spring · medium shade tolerance · to −33 °Fbalsam fir60 ft · blooms mid summer · low shade tolerance · to −43 °Fbalsam poplar80 ft · blooms late spring · high shade tolerance · to −79 °F

Shrubs 88

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Falternateleaf dogwood25 ft · blooms mid spring · low shade tolerance · to −47 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican hornbeam30 ft · blooms mid spring · low shade tolerance · to −34 °F

Wildflowers & perennials 190

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °F

Grasses 156

alkali cordgrass3 ft · blooms late summer · high shade tolerance · to −38 °FAmerican beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °Fbasin wildrye5 ft · blooms early spring · high shade tolerance · to −43 °Fbeaked sedge4 ft · blooms late spring · low shade tolerance · to −38 °F

Vines 4

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °FVirginia creeper1 ft · blooms late spring · medium shade tolerance · to −28 °F

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 Duluth, MN.

Soil in Duluth, MN

The soil mapped at the center of ZIP 55808 is Hapludalfs — very fine sandy loam, well drained.

TextureVery fine sandy loamdrains and warms fast; dries out and needs more feeding
pH5.5moderately acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter5%high
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Udalfs-Eutrudepts complex, 25 to 70 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 55808; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Duluth, MN

Summer high76 °Faverage high, July
Winter low6 °Faverage low, January
Hot days3days a year at 90 °F or more
Freezing nights161nights a year at 32 °F or less
Growing degree days1,706base 50 °F — the season’s usable heat
Longest day15 h 51 mindaylight on June 21
Shortest day8 h 33 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation31.4 inper year, rain and melted snow
Snowfall56 inper year; 101 days with snow on the ground

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 23 °F, low 6 °F 23°6° JanFebruary: average high 27 °F, low 9 °F 27°9° FebMarch: average high 36 °F, low 21 °F 36°21° MarApril: average high 46 °F, low 32 °F 46°32° AprMay: average high 57 °F, low 41 °F 57°41° MayJune: average high 67 °F, low 50 °F 67°50° JunJuly: average high 76 °F, low 58 °F 76°58° JulAugust: average high 75 °F, low 58 °F 75°58° AugSeptember: average high 67 °F, low 50 °F 67°50° SepOctober: average high 53 °F, low 39 °F 53°39° OctNovember: average high 39 °F, low 26 °F 39°26° NovDecember: average high 27 °F, low 13 °F 27°13° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″January: 0.81 in precipitation, 14.5 in snowfall 0.8❄15 JanFebruary: 0.89 in precipitation, 12.4 in snowfall 0.9❄12 FebMarch: 1.41 in precipitation, 9.1 in snowfall 1.4❄9 MarApril: 2.64 in precipitation, 1.7 in snowfall 2.6❄2 AprMay: 3.37 in precipitation 3.4 MayJune: 4.56 in precipitation 4.6 JunJuly: 3.88 in precipitation 3.9 JulAugust: 3.92 in precipitation 3.9 AugSeptember: 3.39 in precipitation 3.4 SepOctober: 3.17 in precipitation, 0.2 in snowfall 3.2 OctNovember: 2.12 in precipitation, 5.8 in snowfall 2.1❄6 NovDecember: 1.29 in precipitation, 12.3 in snowfall 1.3❄12 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Superior, WI (9 mi away); precipitation: Superior, WI (9 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.

558074b
Duluth, MN · 5 mi
558104b
Duluth, MN · 6 mi
557334b
Esko, MN · 6 mi
548804b
Superior, WI · 8 mi
558064b
Duluth, MN · 8 mi
558025a
Duluth, MN · 9 mi
558154b
Duluth, MN · 10 mi
558165a
Duluth, MN · 10 mi

All 13 ZIP codes in Duluth → · Minnesota planting zones →

Questions about 55808

What planting zone is ZIP code 55808?

ZIP code 55808 (Duluth, 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 Duluth, MN?

The median last spring frost (32 °F) near 55808 is May 6; after May 25 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Superior station.

When is the first frost in Duluth, MN?

The median first fall frost near 55808 is October 9, giving a median frost-free growing season of 154 days.

When should I plant tomatoes in 55808?

Start tomato seeds indoors around Mar 11 – Mar 25 and set transplants outside around May 13 – May 27, one to three weeks after the median last frost.

How much rain and snow does 55808 get?

About 31.4 inches of precipitation a year and 56 inches of snowfall (NOAA 1991–2020 normals, Superior station).

How hot do summers get in Duluth, MN?

The average high peaks at 76 °F in July, with about 3 days a year at 90 °F or more.

What kind of soil does 55808 have?

The USDA soil survey maps Hapludalfs at the center of ZIP 55808: very fine sandy loam, well drained, pH about 5.5 (moderately acidic).

Did spring come early in Duluth, MN in 2026?

Spring leaf-out near 55808 came on May 2 in 2026, 4 days later than the 1991–2020 average (Apr 28), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Duluth, MN?

Long-day onions: the longest day near 55808 is 15 h 51 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).