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

Planting zone for 54891 — Washburn, WI

ZIP code 54891 (Washburn, Bayfield County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is May 23 and the first fall frost October 2.

Where ZIP 54891 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 23
First frostOct 2
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 Washburn, 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 Washburn, WI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 23median — 50% chance of a later frost
Safe for tender plantsJune 5only 10% chance of frost after
First fall frostOctober 2median — 10% chance by Sep 17
Growing season131 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 9 and returns around October 14.

From the NOAA station Bayfield Fish Hatchery, WI — 8 miles away, elevation 617 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 54891

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 11 – Apr 25
SpinachSow outdoors · Apr 11 – May 2
Broccoli, cabbageStart indoors · Mar 14 – Mar 28
Broccoli, cabbageTransplant · May 2 – May 16
Onion setsPlant outdoors · Apr 25 – May 9
PotatoesPlant outdoors · May 2 – May 16
LettuceSow outdoors · Apr 25 – May 9
Carrots, beetsSow outdoors · May 2 – May 16
TomatoesStart indoors · Mar 28 – Apr 11
TomatoesTransplant · May 30 – Jun 13
Peppers, eggplantStart indoors · Mar 14 – Mar 28
Peppers, eggplantTransplant · Jun 6 – Jun 20
BeansSow outdoors · May 30 – Jun 13
Sweet cornSow outdoors · May 30 – Jun 13
Cucumbers, squashSow outdoors · May 30 – Jun 13
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 23) 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 54891 came on Apr 29 — about the same time as 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 Wisconsin

486 plants native to the lower 48 states, recorded in Wisconsin, and rated by the USDA to survive −25 °F or colder — the bottom of zone 4b. 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 89

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 178

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 152

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 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 Washburn, WI.

Soil in Washburn, WI

The soil mapped at the center of ZIP 54891 is Portwing — silt loam, moderately well drained.

TextureSilt loama good balance for most vegetables
pH5.9moderately acidic; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter2%moderate
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Portwing-Herbster complex, 0 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 54891; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Washburn, WI

Summer high77 °Faverage high, July
Winter low4 °Faverage low, January
Hot days1days a year at 90 °F or more
Freezing nights185nights a year at 32 °F or less
Growing degree days1,718base 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)
Precipitation33 inper year, rain and melted snow

Average high and low, by month

−10°0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 23 °F, low 4 °F 23°4° JanFebruary: average high 26 °F, low 6 °F 26°6° FebMarch: average high 37 °F, low 17 °F 37°17° MarApril: average high 49 °F, low 29 °F 49°29° AprMay: average high 60 °F, low 40 °F 60°40° MayJune: average high 71 °F, low 50 °F 71°50° JunJuly: average high 77 °F, low 56 °F 77°56° JulAugust: average high 76 °F, low 55 °F 76°55° AugSeptember: average high 68 °F, low 48 °F 68°48° SepOctober: average high 55 °F, low 36 °F 55°36° OctNovember: average high 40 °F, low 25 °F 40°25° NovDecember: average high 28 °F, low 12 °F 28°12° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 1.31 in precipitation 1.3 JanFebruary: 1.08 in precipitation 1.1 FebMarch: 1.61 in precipitation 1.6 MarApril: 2.61 in precipitation 2.6 AprMay: 3.54 in precipitation 3.5 MayJune: 4.19 in precipitation 4.2 JunJuly: 4.28 in precipitation 4.3 JulAugust: 3.86 in precipitation 3.9 AugSeptember: 3.62 in precipitation 3.6 SepOctober: 3.29 in precipitation 3.3 OctNovember: 1.97 in precipitation 2.0 NovDecember: 1.60 in precipitation 1.6 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Bayfield Fish Hatchery, WI (8 mi away); precipitation: Ashland Exp Farm, WI (8 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

548274b
Cornucopia, WI · 10 mi
548065a
Ashland, WI · 12 mi
548145a
Bayfield, WI · 12 mi
548444b
Herbster, WI · 13 mi
548164b
Benoit, WI · 14 mi
548615a
Odanah, WI · 17 mi
548564b
Mason, WI · 19 mi
548554b
Marengo, WI · 23 mi

Wisconsin planting zones →

Questions about 54891

What planting zone is ZIP code 54891?

ZIP code 54891 (Washburn, WI) 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 Washburn, WI?

The median last spring frost (32 °F) near 54891 is May 23; after June 5 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Bayfield Fish Hatchery station.

When is the first frost in Washburn, WI?

The median first fall frost near 54891 is October 2, giving a median frost-free growing season of 131 days.

When should I plant tomatoes in 54891?

Start tomato seeds indoors around Mar 28 – Apr 11 and set transplants outside around May 30 – Jun 13, one to three weeks after the median last frost.

How much rain and snow does 54891 get?

About 33 inches of precipitation a year (NOAA 1991–2020 normals, Ashland Exp Farm station).

How hot do summers get in Washburn, WI?

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 54891 have?

The USDA soil survey maps Portwing at the center of ZIP 54891: silt loam, moderately well drained, pH about 5.9 (moderately acidic).

Did spring come early in Washburn, WI in 2026?

Spring leaf-out near 54891 came on Apr 29 in 2026, about the same as the 1991–2020 average (Apr 28), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Washburn, WI?

Long-day onions: the longest day near 54891 is 15 h 51 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).