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

Planting zone for 54216 — Kewaunee, WI

ZIP code 54216 (Kewaunee, Kewaunee County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is May 1 and the first fall frost October 18.

Where ZIP 54216 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.

Zone5b−15 to −10 °F

Coldest night−26.1 to −23.3 °C

Last frostMay 1

First frostOct 18

2012 zone5b

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 5b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Kewaunee, 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 Kewaunee, WI

JanFebMarAprMayJunJulAugSepOctNovDec

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

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

Safe for tender plantsMay 17only 10% chance of frost after

First fall frostOctober 18median — 10% chance by Oct 2

Growing season168 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 18 and returns around October 31.

From the NOAA station Kewaunee, WI — 4 miles away, elevation 594 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 54216

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 20 – Apr 3

SpinachSow outdoors · Mar 20 – Apr 10

Broccoli, cabbageStart indoors · Feb 20 – Mar 6

Broccoli, cabbageTransplant · Apr 10 – Apr 24

Onion setsPlant outdoors · Apr 3 – Apr 17

PotatoesPlant outdoors · Apr 10 – Apr 24

LettuceSow outdoors · Apr 3 – Apr 17

Carrots, beetsSow outdoors · Apr 10 – Apr 24

TomatoesStart indoors · Mar 6 – Mar 20

TomatoesTransplant · May 8 – May 22

Peppers, eggplantStart indoors · Feb 20 – Mar 6

Peppers, eggplantTransplant · May 15 – May 29

BeansSow outdoors · May 8 – May 22

Sweet cornSow outdoors · May 8 – May 22

Cucumbers, squashSow outdoors · May 8 – May 22

Fall lettuce, spinachSow outdoors · Aug 23 – Sep 6

GarlicPlant cloves · Oct 4 – Nov 8

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 1) and first fall frost (Oct 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 54216 came on Apr 22 — about the same time as the 1991–2020 average (Apr 22).

average
Apr 222026
Apr 22

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 5b in Wisconsin

518 plants native to the lower 48 states, recorded in Wisconsin, and rated by the USDA to survive −15 °F or colder — the bottom of zone 5b. 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 Kewaunee, WI.

Soil in Kewaunee, WI

The soil mapped at the center of ZIP 54216 is Hortonville — silt loam, well drained.

TextureSilt loama good balance for most vegetables

pH6.7neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter2%moderate

Hydrologic groupCwater soaks in slowly

Farmland classprime farmlandUSDA classification

Map unit: Hortonville-Symco silt loams, 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 54216; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Kewaunee, WI

Summer high76 °Faverage high, July

Winter low12 °Faverage low, January

Hot days2days a year at 90 °F or more

Freezing nights145nights a year at 32 °F or less

Growing degree days2,010base 50 °F — the season’s usable heat

Longest day15 h 33 mindaylight on June 21

Shortest day8 h 50 mindaylight on December 21

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

Precipitation31.1 inper year, rain and melted snow

Snowfall48 inper year; 80 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: Kewaunee, WI (4 mi away); precipitation: Kewaunee, WI (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5b.

542405b

Tisch Mills, WI · 8 mi

542175b

Luxemburg, WI · 11 mi

New Franken, WI · 15 mi

542415b

Two Rivers, WI · 15 mi

Wisconsin planting zones →

Questions about 54216

What planting zone is ZIP code 54216?

ZIP code 54216 (Kewaunee, WI) is in USDA hardiness zone 5b on the 2023 map: the coldest night of an average winter reaches −15 to −10 °F (−26.1 to −23.3 °C).

When is the last frost in Kewaunee, WI?

The median last spring frost (32 °F) near 54216 is May 1; after May 17 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Kewaunee station.

When is the first frost in Kewaunee, WI?

The median first fall frost near 54216 is October 18, giving a median frost-free growing season of 168 days.

When should I plant tomatoes in 54216?

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

How much rain and snow does 54216 get?

About 31.1 inches of precipitation a year and 48 inches of snowfall (NOAA 1991–2020 normals, Kewaunee station).

How hot do summers get in Kewaunee, WI?

The average high peaks at 76 °F in July, with about 2 days a year at 90 °F or more.

What kind of soil does 54216 have?

The USDA soil survey maps Hortonville at the center of ZIP 54216: silt loam, well drained, pH about 6.7 (neutral).

Did spring come early in Kewaunee, WI in 2026?

Spring leaf-out near 54216 came on Apr 22 in 2026, about the same as the 1991–2020 average (Apr 22), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Kewaunee, WI?

Long-day onions: the longest day near 54216 is 15 h 33 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).