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

Planting zone for Manitowoc, WI

Manitowoc, WI is in USDA zone 5b across its 2 ZIP codes. The median last spring frost is April 30 and the first fall frost October 20.

Manitowoc on the zone map

Outlined: its 1 ZIP code areas · 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

ZIP codes2

Last frostApr 30

First frostOct 20

Growing season171 days

5b 2 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Manitowoc, 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 Manitowoc, WI

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 30median — 50% chance of a later frost

Safe for tender plantsMay 15only 10% chance of frost after

First fall frostOctober 20median — 10% chance by Oct 3

Growing season171 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 16 and returns around November 1.

From the NOAA station Manitowoc, WI, elevation 584 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 Manitowoc

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 19 – Apr 2

SpinachSow outdoors · Mar 19 – Apr 9

Broccoli, cabbageStart indoors · Feb 19 – Mar 5

Broccoli, cabbageTransplant · Apr 9 – Apr 23

Onion setsPlant outdoors · Apr 2 – Apr 16

PotatoesPlant outdoors · Apr 9 – Apr 23

LettuceSow outdoors · Apr 2 – Apr 16

Carrots, beetsSow outdoors · Apr 9 – Apr 23

TomatoesStart indoors · Mar 5 – Mar 19

TomatoesTransplant · May 7 – May 21

Peppers, eggplantStart indoors · Feb 19 – Mar 5

Peppers, eggplantTransplant · May 14 – May 28

BeansSow outdoors · May 7 – May 21

Sweet cornSow outdoors · May 7 – May 21

Cucumbers, squashSow outdoors · May 7 – May 21

Fall lettuce, spinachSow outdoors · Aug 25 – Sep 8

GarlicPlant cloves · Oct 6 – Nov 10

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 30) and first fall frost (Oct 20) 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 54221 came on Apr 17 — 6 days earlier than the 1991–2020 average (Apr 23).

average
Apr 232026
Apr 17

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 Manitowoc, WI.

Soil in Manitowoc, WI

The USDA soil survey has no mapped soil at the center of this ZIP code (water, or an area not yet surveyed).

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 54221; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Manitowoc, WI

Summer high76 °Faverage high, July

Winter low12 °Faverage low, January

Hot days1days a year at 90 °F or more

Freezing nights140nights a year at 32 °F or less

Growing degree days1,933base 50 °F — the season’s usable heat

Longest day15 h 30 mindaylight on June 21

Shortest day8 h 52 mindaylight on December 21

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

Precipitation32 inper year, rain and melted snow

Snowfall46 inper year; 78 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: Two Rivers, WI (2 mi away); precipitation: Two Rivers, WI (2 mi away). Daylight is calculated from latitude.

ZIP codes in Manitowoc

Wisconsin planting zones →

Questions about Manitowoc

What planting zone is Manitowoc, WI?

Manitowoc, WI is in USDA hardiness zone 5b on the 2023 map (5b: −15 to −10 °F).

When is the last frost in Manitowoc, WI?

The median last spring frost is April 30 and the median first fall frost is October 20 (NOAA 1991–2020 normals, Manitowoc station).

When can I plant a garden in Manitowoc, WI?

Cool-season crops like peas and spinach go in around Mar 19 – Apr 9; tomatoes, peppers, beans and squash after about May 7, once frost risk has passed.

What kind of onions grow in Manitowoc, WI?

Long-day onions: the longest day is 15 h 30 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

How much rain and snow does Manitowoc, WI get?

About 32 inches of precipitation a year and 46 inches of snowfall (NOAA 1991–2020 normals).