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

Planting zone for 54102 — Amberg, WI

ZIP code 54102 (Amberg, Marinette County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is May 26 and the first fall frost September 22.

Where ZIP 54102 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 26

First frostSep 22

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 Amberg, 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 Amberg, WI

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 26median — 50% chance of a later frost

Safe for tender plantsJune 11only 10% chance of frost after

First fall frostSeptember 22median — 10% chance by Sep 6

Growing season118 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 14 and returns around October 3.

From the NOAA station Crivitz High Falls, WI — 13 miles away, elevation 951 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 54102

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 14 – Apr 28

SpinachSow outdoors · Apr 14 – May 5

Broccoli, cabbageStart indoors · Mar 17 – Mar 31

Broccoli, cabbageTransplant · May 5 – May 19

Onion setsPlant outdoors · Apr 28 – May 12

PotatoesPlant outdoors · May 5 – May 19

LettuceSow outdoors · Apr 28 – May 12

Carrots, beetsSow outdoors · May 5 – May 19

TomatoesStart indoors · Mar 31 – Apr 14

TomatoesTransplant · Jun 2 – Jun 16

Peppers, eggplantStart indoors · Mar 17 – Mar 31

Peppers, eggplantTransplant · Jun 9 – Jun 23

BeansSow outdoors · Jun 2 – Jun 16

Sweet cornSow outdoors · Jun 2 – Jun 16

Cucumbers, squashSow outdoors · Jun 2 – Jun 16

Fall lettuce, spinachSow outdoors · Jul 28 – Aug 11

GarlicPlant cloves · Sep 8 – Oct 13

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 26) and first fall frost (Sep 22) 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 54102 came on Apr 18 — 5 days earlier than the 1991–2020 average (Apr 23).

average
Apr 232026
Apr 18

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.

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 Amberg, WI.

Soil in Amberg, WI

The soil mapped at the center of ZIP 54102 is Mancelona — loamy sand, somewhat excessively drained.

TextureLoamy sanddrains and warms fast; dries out and needs more feeding

pH6.2slightly acidic; most vegetables like 6.0–7.0

DrainageSomewhat excessively drainednatural drainage class

Organic matter1.75%low — add compost

Hydrologic groupAwater soaks in fast

Farmland classFarmland of statewide importanceUSDA classification

Map unit: Mancelona loamy sand, 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 54102; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Amberg, WI

Summer high79 °Faverage high, July

Winter low4 °Faverage low, January

Hot days8days a year at 90 °F or more

Freezing nights194nights a year at 32 °F or less

Growing degree days1,842base 50 °F — the season’s usable heat

Longest day15 h 41 mindaylight on June 21

Shortest day8 h 42 mindaylight on December 21

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

Precipitation32.9 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Crivitz High Falls, WI (13 mi away); precipitation: Wausaukee, WI (9 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 4b.

541564b

Pembine, WI · 8 mi

541774b

Wausaukee, WI · 10 mi

541194b

Dunbar, WI · 12 mi

541044b

Athelstane, WI · 13 mi

Wisconsin planting zones →

Questions about 54102

What planting zone is ZIP code 54102?

ZIP code 54102 (Amberg, 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 Amberg, WI?

The median last spring frost (32 °F) near 54102 is May 26; after June 11 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Crivitz High Falls station.

When is the first frost in Amberg, WI?

The median first fall frost near 54102 is September 22, giving a median frost-free growing season of 118 days.

When should I plant tomatoes in 54102?

Start tomato seeds indoors around Mar 31 – Apr 14 and set transplants outside around Jun 2 – Jun 16, one to three weeks after the median last frost.

How much rain and snow does 54102 get?

About 32.9 inches of precipitation a year (NOAA 1991–2020 normals, Wausaukee station).

How hot do summers get in Amberg, WI?

The average high peaks at 79 °F in July, with about 8 days a year at 90 °F or more.

What kind of soil does 54102 have?

The USDA soil survey maps Mancelona at the center of ZIP 54102: loamy sand, somewhat excessively drained, pH about 6.2 (slightly acidic).

Did spring come early in Amberg, WI in 2026?

Spring leaf-out near 54102 came on Apr 18 in 2026, 5 days earlier than the 1991–2020 average (Apr 23), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Amberg, WI?

Long-day onions: the longest day near 54102 is 15 h 41 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).