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

Planting zone for 54928 — Caroline, WI

ZIP code 54928 (Caroline, Shawano County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 13 and the first fall frost September 30.

Where ZIP 54928 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 13

First frostSep 30

2012 zone4b

Was 4b on the 2012 map — half a zone warmer now. 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 Caroline, 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 Caroline, WI

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 13median — 50% chance of a later frost

Safe for tender plantsMay 26only 10% chance of frost after

First fall frostSeptember 30median — 10% chance by Sep 17

Growing season141 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 2 and returns around October 12.

From the NOAA station Stockbridge-Munsee Rsvn, WI — 8 miles away, elevation 1,050 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 54928

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 1 – Apr 15

SpinachSow outdoors · Apr 1 – Apr 22

Broccoli, cabbageStart indoors · Mar 4 – Mar 18

Broccoli, cabbageTransplant · Apr 22 – May 6

Onion setsPlant outdoors · Apr 15 – Apr 29

PotatoesPlant outdoors · Apr 22 – May 6

LettuceSow outdoors · Apr 15 – Apr 29

Carrots, beetsSow outdoors · Apr 22 – May 6

TomatoesStart indoors · Mar 18 – Apr 1

TomatoesTransplant · May 20 – Jun 3

Peppers, eggplantStart indoors · Mar 4 – Mar 18

Peppers, eggplantTransplant · May 27 – Jun 10

BeansSow outdoors · May 20 – Jun 3

Sweet cornSow outdoors · May 20 – Jun 3

Cucumbers, squashSow outdoors · May 20 – Jun 3

Fall lettuce, spinachSow outdoors · Aug 5 – Aug 19

GarlicPlant cloves · Sep 16 – Oct 21

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 13) and first fall frost (Sep 30) 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 54928 came on Apr 15 — 4 days earlier than the 1991–2020 average (Apr 19).

average
Apr 192026
Apr 15

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.

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 Caroline, WI.

Soil in Caroline, WI

The soil mapped at the center of ZIP 54928 is Kennan — sandy loam, well drained.

TextureSandy loamdrains and warms fast; dries out and needs more feeding

pH5.5moderately acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter5%high

Hydrologic groupAwater soaks in fast

Farmland classNot prime farmlandUSDA classification

Map unit: Kennan, very bouldery and Kennan sandy loams, 15 to 30 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 54928; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Caroline, WI

Summer high78 °Faverage high, July

Winter low5 °Faverage low, January

Hot days2days a year at 90 °F or more

Freezing nights178nights a year at 32 °F or less

Growing degree days1,974base 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)

Precipitation33 inper year, rain and melted snow

Snowfall44 inper year; 94 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: Stockbridge-Munsee Rsvn, WI (8 mi away); precipitation: Clintonville, WI (11 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

Clintonville, WI · 10 mi

549335a

Embarrass, WI · 10 mi

Wisconsin planting zones →

Questions about 54928

What planting zone is ZIP code 54928?

ZIP code 54928 (Caroline, 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 Caroline, WI?

The median last spring frost (32 °F) near 54928 is May 13; after May 26 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Stockbridge-Munsee Rsvn station.

When is the first frost in Caroline, WI?

The median first fall frost near 54928 is September 30, giving a median frost-free growing season of 141 days.

When should I plant tomatoes in 54928?

Start tomato seeds indoors around Mar 18 – Apr 1 and set transplants outside around May 20 – Jun 3, one to three weeks after the median last frost.

How much rain and snow does 54928 get?

About 33 inches of precipitation a year and 44 inches of snowfall (NOAA 1991–2020 normals, Clintonville station).

How hot do summers get in Caroline, WI?

The average high peaks at 78 °F in July, with about 2 days a year at 90 °F or more.

What kind of soil does 54928 have?

The USDA soil survey maps Kennan at the center of ZIP 54928: sandy loam, well drained, pH about 5.5 (moderately acidic).

Did spring come early in Caroline, WI in 2026?

Spring leaf-out near 54928 came on Apr 15 in 2026, 4 days earlier than the 1991–2020 average (Apr 19), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Caroline, WI?

Long-day onions: the longest day near 54928 is 15 h 35 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 54928 change?

Yes. The 2012 USDA map put 54928 in zone 4b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.