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

Planting zone for 54171 — Sobieski, WI

ZIP code 54171 (Sobieski, Oconto County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 7 and the first fall frost October 9.

Where ZIP 54171 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.

Zone5a−20 to −15 °F
Coldest night−28.9 to −26.1 °C
Last frostMay 7
First frostOct 9
2012 zone5a

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 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Sobieski, WI…

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 Sobieski, WI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 7median — 50% chance of a later frost
Safe for tender plantsMay 22only 10% chance of frost after
First fall frostOctober 9median — 10% chance by Sep 23
Growing season154 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 27 and returns around October 25.

From the NOAA station Green Bay Botanical, WI — 12 miles away, elevation 696 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 54171

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 26 – Apr 9
SpinachSow outdoors · Mar 26 – Apr 16
Broccoli, cabbageStart indoors · Feb 26 – Mar 12
Broccoli, cabbageTransplant · Apr 16 – Apr 30
Onion setsPlant outdoors · Apr 9 – Apr 23
PotatoesPlant outdoors · Apr 16 – Apr 30
LettuceSow outdoors · Apr 9 – Apr 23
Carrots, beetsSow outdoors · Apr 16 – Apr 30
TomatoesStart indoors · Mar 12 – Mar 26
TomatoesTransplant · May 14 – May 28
Peppers, eggplantStart indoors · Feb 26 – Mar 12
Peppers, eggplantTransplant · May 21 – Jun 4
BeansSow outdoors · May 14 – May 28
Sweet cornSow outdoors · May 14 – May 28
Cucumbers, squashSow outdoors · May 14 – May 28
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 7) 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 54171 came on Apr 15 — 5 days earlier than the 1991–2020 average (Apr 20).

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 5a in Wisconsin

510 plants native to the lower 48 states, recorded in Wisconsin, and rated by the USDA to survive −20 °F or colder — the bottom of zone 5a. Each links to its USDA PLANTS profile.

Trees 48

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican chestnut115 ft · blooms early summer · high shade tolerance · to −33 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °Farborvitae50 ft · blooms mid spring · medium shade tolerance · to −33 °F

Shrubs 93

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 191

alkali buttercup1 ft · blooms late spring · low 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 °FAmerican pokeweed7 ft · blooms mid summer · low shade tolerance · to −33 °F

Grasses 158

American 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 °Fbeaked sedge4 ft · blooms late spring · low shade tolerance · to −38 °Fbeaked spikerush3 ft · blooms late spring · high shade tolerance · to −28 °FBebb's sedge3 ft · blooms late spring · low shade tolerance · to −38 °F

Vines 5

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 °Fsummer grape30 ft · blooms late spring · low shade tolerance · to −23 °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 Sobieski, WI.

Soil in Sobieski, WI

The soil mapped at the center of ZIP 54171 is Rousseau — fine sand, moderately well drained.

TextureFine sanddrains and warms fast; dries out and needs more feeding
pH5.3strongly acidic; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter1.5%low — add compost
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Rousseau fine sand, 1 to 6 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 54171; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Sobieski, WI

Summer high80 °Faverage high, July
Winter low9 °Faverage low, January
Hot days6days a year at 90 °F or more
Freezing nights159nights a year at 32 °F or less
Growing degree days2,279base 50 °F — the season’s usable heat
Longest day15 h 35 mindaylight on June 21
Shortest day8 h 48 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation30.9 inper year, rain and melted snow
Snowfall50 inper year; 93 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 25 °F, low 9 °F 25°9° JanFebruary: average high 29 °F, low 11 °F 29°11° FebMarch: average high 40 °F, low 21 °F 40°21° MarApril: average high 54 °F, low 33 °F 54°33° AprMay: average high 67 °F, low 44 °F 67°44° MayJune: average high 75 °F, low 55 °F 75°55° JunJuly: average high 80 °F, low 59 °F 80°59° JulAugust: average high 78 °F, low 57 °F 78°57° AugSeptember: average high 71 °F, low 49 °F 71°49° SepOctober: average high 58 °F, low 39 °F 58°39° OctNovember: average high 44 °F, low 27 °F 44°27° NovDecember: average high 31 °F, low 17 °F 31°17° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″January: 1.29 in precipitation, 10.7 in snowfall 1.3❄11 JanFebruary: 1.13 in precipitation, 13.7 in snowfall 1.1❄14 FebMarch: 1.81 in precipitation, 6.7 in snowfall 1.8❄7 MarApril: 3.15 in precipitation, 4.4 in snowfall 3.1❄4 AprMay: 3.37 in precipitation 3.4 MayJune: 3.54 in precipitation 3.5 JunJuly: 3.58 in precipitation 3.6 JulAugust: 3.42 in precipitation 3.4 AugSeptember: 3.44 in precipitation 3.4 SepOctober: 2.79 in precipitation, 0.3 in snowfall 2.8 OctNovember: 1.79 in precipitation, 1.7 in snowfall 1.8❄2 NovDecember: 1.54 in precipitation, 12.9 in snowfall 1.5❄13 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Green Bay Botanical, WI (12 mi away); precipitation: Pulaski Wwtp, WI (7 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

541415b
Little Suamico, WI · 5 mi
541015a
Abrams, WI · 5 mi
541735b
Suamico, WI · 7 mi
541375a
Krakow, WI · 8 mi
543135b
Green Bay, WI · 9 mi
541625a
Pulaski, WI · 9 mi
541545a
Oconto Falls, WI · 12 mi
543035b
Green Bay, WI · 12 mi

Wisconsin planting zones →

Questions about 54171

What planting zone is ZIP code 54171?

ZIP code 54171 (Sobieski, WI) is in USDA hardiness zone 5a on the 2023 map: the coldest night of an average winter reaches −20 to −15 °F (−28.9 to −26.1 °C).

When is the last frost in Sobieski, WI?

The median last spring frost (32 °F) near 54171 is May 7; after May 22 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Green Bay Botanical station.

When is the first frost in Sobieski, WI?

The median first fall frost near 54171 is October 9, giving a median frost-free growing season of 154 days.

When should I plant tomatoes in 54171?

Start tomato seeds indoors around Mar 12 – Mar 26 and set transplants outside around May 14 – May 28, one to three weeks after the median last frost.

How much rain and snow does 54171 get?

About 30.9 inches of precipitation a year and 50 inches of snowfall (NOAA 1991–2020 normals, Pulaski Wwtp station).

How hot do summers get in Sobieski, WI?

The average high peaks at 80 °F in July, with about 6 days a year at 90 °F or more.

What kind of soil does 54171 have?

The USDA soil survey maps Rousseau at the center of ZIP 54171: fine sand, moderately well drained, pH about 5.3 (strongly acidic).

Did spring come early in Sobieski, WI in 2026?

Spring leaf-out near 54171 came on Apr 15 in 2026, 5 days earlier than the 1991–2020 average (Apr 20), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Sobieski, WI?

Long-day onions: the longest day near 54171 is 15 h 35 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).