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

Planting zone for 54559 — Saxon, WI

ZIP code 54559 (Saxon, Iron County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is May 23 and the first fall frost October 1.

Where ZIP 54559 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 23

First frostOct 1

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 Saxon, 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 Saxon, WI

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 23median — 50% chance of a later frost

Safe for tender plantsJune 5only 10% chance of frost after

First fall frostOctober 1median — 10% chance by Sep 18

Growing season132 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 8 and returns around October 14.

From the NOAA station Saxon 1wsw, WI — 2 miles away, elevation 1,165 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 54559

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 11 – Apr 25

SpinachSow outdoors · Apr 11 – May 2

Broccoli, cabbageStart indoors · Mar 14 – Mar 28

Broccoli, cabbageTransplant · May 2 – May 16

Onion setsPlant outdoors · Apr 25 – May 9

PotatoesPlant outdoors · May 2 – May 16

LettuceSow outdoors · Apr 25 – May 9

Carrots, beetsSow outdoors · May 2 – May 16

TomatoesStart indoors · Mar 28 – Apr 11

TomatoesTransplant · May 30 – Jun 13

Peppers, eggplantStart indoors · Mar 14 – Mar 28

Peppers, eggplantTransplant · Jun 6 – Jun 20

BeansSow outdoors · May 30 – Jun 13

Sweet cornSow outdoors · May 30 – Jun 13

Cucumbers, squashSow outdoors · May 30 – Jun 13

Fall lettuce, spinachSow outdoors · Aug 6 – Aug 20

GarlicPlant cloves · Sep 17 – Oct 22

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 23) and first fall frost (Oct 1) 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 54559 came on Apr 24 — 3 days earlier than the 1991–2020 average (Apr 27).

average
Apr 272026
Apr 24

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 Saxon, WI.

Soil in Saxon, WI

The soil mapped at the center of ZIP 54559 is Kellogg — moderately decomposed plant material, moderately well drained.

TextureModerately decomposed plant materialtop layer

pH4.6strongly acidic; most vegetables like 6.0–7.0

DrainageModerately well drainednatural drainage class

Organic matter75%high

Hydrologic groupC/Dslow when drained; wet otherwise

Farmland classNot prime farmlandUSDA classification

Map unit: Kellogg-Allendale-Ashwabay complex, 2 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 54559; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Saxon, WI

Summer high78 °Faverage high, July

Winter low5 °Faverage low, January

Hot days3days a year at 90 °F or more

Freezing nights188nights a year at 32 °F or less

Growing degree days1,892base 50 °F — the season’s usable heat

Longest day15 h 49 mindaylight on June 21

Shortest day8 h 34 mindaylight on December 21

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

Precipitation37.5 inper year, rain and melted snow

Snowfall134 inper year

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Saxon 1wsw, WI (2 mi away); precipitation: Saxon 1wsw, WI (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

548615a

Odanah, WI · 10 mi

545364a

Iron Belt, WI · 13 mi

545254b

Gile, WI · 13 mi

548464b

High Bridge, WI · 14 mi

Wisconsin planting zones →

Questions about 54559

What planting zone is ZIP code 54559?

ZIP code 54559 (Saxon, 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 Saxon, WI?

The median last spring frost (32 °F) near 54559 is May 23; after June 5 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Saxon 1wsw station.

When is the first frost in Saxon, WI?

The median first fall frost near 54559 is October 1, giving a median frost-free growing season of 132 days.

When should I plant tomatoes in 54559?

Start tomato seeds indoors around Mar 28 – Apr 11 and set transplants outside around May 30 – Jun 13, one to three weeks after the median last frost.

How much rain and snow does 54559 get?

About 37.5 inches of precipitation a year and 134 inches of snowfall (NOAA 1991–2020 normals, Saxon 1wsw station).

How hot do summers get in Saxon, WI?

The average high peaks at 78 °F in July, with about 3 days a year at 90 °F or more.

What kind of soil does 54559 have?

The USDA soil survey maps Kellogg at the center of ZIP 54559: moderately decomposed plant material, moderately well drained, pH about 4.6 (strongly acidic).

Did spring come early in Saxon, WI in 2026?

Spring leaf-out near 54559 came on Apr 24 in 2026, 3 days earlier than the 1991–2020 average (Apr 27), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Saxon, WI?

Long-day onions: the longest day near 54559 is 15 h 49 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).