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

Planting zone for 54221 — Manitowoc, WI

ZIP code 54221 (Manitowoc, Manitowoc County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is April 27 and the first fall frost October 21.

Where ZIP 54221 is

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 frostApr 27
First frostOct 21
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 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 27median — 50% chance of a later frost
Safe for tender plantsMay 10only 10% chance of frost after
First fall frostOctober 21median — 10% chance by Oct 4
Growing season175 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 14 and returns around November 1.

From the NOAA station Two Rivers, WI — 2 miles away, elevation 591 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 54221

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 16 – Mar 30
SpinachSow outdoors · Mar 16 – Apr 6
Broccoli, cabbageStart indoors · Feb 16 – Mar 2
Broccoli, cabbageTransplant · Apr 6 – Apr 20
Onion setsPlant outdoors · Mar 30 – Apr 13
PotatoesPlant outdoors · Apr 6 – Apr 20
LettuceSow outdoors · Mar 30 – Apr 13
Carrots, beetsSow outdoors · Apr 6 – Apr 20
TomatoesStart indoors · Mar 2 – Mar 16
TomatoesTransplant · May 4 – May 18
Peppers, eggplantStart indoors · Feb 16 – Mar 2
Peppers, eggplantTransplant · May 11 – May 25
BeansSow outdoors · May 4 – May 18
Sweet cornSow outdoors · May 4 – May 18
Cucumbers, squashSow outdoors · May 4 – May 18
Fall lettuce, spinachSow outdoors · Aug 26 – Sep 9
GarlicPlant cloves · Oct 7 – Nov 11
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 27) and first fall frost (Oct 21) 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).

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.

Trees 49

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 197

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 159

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 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

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 27 °F, low 12 °F 27°12° JanFebruary: average high 30 °F, low 14 °F 30°14° FebMarch: average high 38 °F, low 23 °F 38°23° MarApril: average high 49 °F, low 34 °F 49°34° AprMay: average high 59 °F, low 44 °F 59°44° MayJune: average high 69 °F, low 53 °F 69°53° JunJuly: average high 76 °F, low 59 °F 76°59° JulAugust: average high 76 °F, low 60 °F 76°60° AugSeptember: average high 68 °F, low 52 °F 68°52° SepOctober: average high 56 °F, low 41 °F 56°41° OctNovember: average high 43 °F, low 29 °F 43°29° NovDecember: average high 33 °F, low 19 °F 33°19° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″January: 1.78 in precipitation, 14.8 in snowfall 1.8❄15 JanFebruary: 1.45 in precipitation, 11.3 in snowfall 1.4❄11 FebMarch: 2.04 in precipitation, 5.7 in snowfall 2.0❄6 MarApril: 3.40 in precipitation, 1.9 in snowfall 3.4❄2 AprMay: 3.43 in precipitation 3.4 MayJune: 4.15 in precipitation 4.2 JunJuly: 3.34 in precipitation 3.3 JulAugust: 3.23 in precipitation 3.2 AugSeptember: 2.52 in precipitation 2.5 SepOctober: 2.77 in precipitation, 0.2 in snowfall 2.8 OctNovember: 2.12 in precipitation, 2.2 in snowfall 2.1❄2 NovDecember: 1.80 in precipitation, 10 in snowfall 1.8❄10 Dec

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.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5b.

542415b
Two Rivers, WI · 6 mi
542205b
Manitowoc, WI · 7 mi
542145b
Francis Creek, WI · 7 mi
542285b
Mishicot, WI · 10 mi
542475b
Whitelaw, WI · 11 mi
542155b
Kellnersville, WI · 12 mi
542405b
Tisch Mills, WI · 14 mi
542275b
Maribel, WI · 15 mi

All 2 ZIP codes in Manitowoc → · Wisconsin planting zones →

Questions about 54221

What planting zone is ZIP code 54221?

ZIP code 54221 (Manitowoc, 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 Manitowoc, WI?

The median last spring frost (32 °F) near 54221 is April 27; after May 10 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Two Rivers station.

When is the first frost in Manitowoc, WI?

The median first fall frost near 54221 is October 21, giving a median frost-free growing season of 175 days.

When should I plant tomatoes in 54221?

Start tomato seeds indoors around Mar 2 – Mar 16 and set transplants outside around May 4 – May 18, one to three weeks after the median last frost.

How much rain and snow does 54221 get?

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

How hot do summers get in Manitowoc, WI?

The average high peaks at 76 °F in July, with about 1 days a year at 90 °F or more.

Did spring come early in Manitowoc, WI in 2026?

Spring leaf-out near 54221 came on Apr 17 in 2026, 6 days earlier than the 1991–2020 average (Apr 23), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Manitowoc, WI?

Long-day onions: the longest day near 54221 is 15 h 30 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).