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

Planting zone for 54455 — Mosinee, WI

ZIP code 54455 (Mosinee, Marathon County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 6 and the first fall frost October 4.

Where ZIP 54455 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 6
First frostOct 4
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 Mosinee, 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 Mosinee, WI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 6median — 50% chance of a later frost
Safe for tender plantsMay 21only 10% chance of frost after
First fall frostOctober 4median — 10% chance by Sep 21
Growing season150 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 26 and returns around October 16.

From the NOAA station Wausau Dwtn Airport, WI — 11 miles away, elevation 1,181 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 54455

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 25 – Apr 8
SpinachSow outdoors · Mar 25 – Apr 15
Broccoli, cabbageStart indoors · Feb 25 – Mar 11
Broccoli, cabbageTransplant · Apr 15 – Apr 29
Onion setsPlant outdoors · Apr 8 – Apr 22
PotatoesPlant outdoors · Apr 15 – Apr 29
LettuceSow outdoors · Apr 8 – Apr 22
Carrots, beetsSow outdoors · Apr 15 – Apr 29
TomatoesStart indoors · Mar 11 – Mar 25
TomatoesTransplant · May 13 – May 27
Peppers, eggplantStart indoors · Feb 25 – Mar 11
Peppers, eggplantTransplant · May 20 – Jun 3
BeansSow outdoors · May 13 – May 27
Sweet cornSow outdoors · May 13 – May 27
Cucumbers, squashSow outdoors · May 13 – May 27
Fall lettuce, spinachSow outdoors · Aug 9 – Aug 23
GarlicPlant cloves · Sep 20 – Oct 25
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 6) and first fall frost (Oct 4) 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 54455 came on Apr 15 — 4 days earlier than the 1991–2020 average (Apr 19).

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.

Trees 48

Shrubs 93

Wildflowers & perennials 191

Grasses 158

Vines 5

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 Mosinee, WI.

Soil in Mosinee, WI

The soil mapped at the center of ZIP 54455 is Mosinee — sandy loam, well drained.

TextureSandy loamdrains and warms fast; dries out and needs more feeding
pH5.9moderately acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2.5%moderate
Hydrologic groupAwater soaks in fast
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Mosinee sandy loam, 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 54455; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Mosinee, WI

Summer high80 °Faverage high, July
Winter low7 °Faverage low, January
Hot days5days a year at 90 °F or more
Freezing nights163nights a year at 32 °F or less
Growing degree days2,238base 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)
Precipitation34.1 inper year, rain and melted snow
Snowfall54 inper year

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 23 °F, low 7 °F 23°7° JanFebruary: average high 27 °F, low 10 °F 27°10° FebMarch: average high 40 °F, low 21 °F 40°21° MarApril: average high 54 °F, low 32 °F 54°32° AprMay: average high 67 °F, low 45 °F 67°45° MayJune: average high 76 °F, low 55 °F 76°55° JunJuly: average high 80 °F, low 59 °F 80°59° JulAugust: average high 78 °F, low 57 °F 78°57° AugSeptember: average high 70 °F, low 49 °F 70°49° SepOctober: average high 56 °F, low 37 °F 56°37° OctNovember: average high 40 °F, low 25 °F 40°25° NovDecember: average high 28 °F, low 14 °F 28°14° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″January: 1.20 in precipitation, 14.1 in snowfall 1.2❄14 JanFebruary: 1.09 in precipitation, 10.9 in snowfall 1.1❄11 FebMarch: 1.62 in precipitation, 6.9 in snowfall 1.6❄7 MarApril: 3.18 in precipitation, 5.2 in snowfall 3.2❄5 AprMay: 4.01 in precipitation, 0.2 in snowfall 4.0 MayJune: 4.70 in precipitation 4.7 JunJuly: 3.84 in precipitation 3.8 JulAugust: 4.22 in precipitation 4.2 AugSeptember: 3.75 in precipitation 3.8 SepOctober: 3.10 in precipitation, 0.4 in snowfall 3.1 OctNovember: 1.88 in precipitation, 5.7 in snowfall 1.9❄6 NovDecember: 1.48 in precipitation, 10.6 in snowfall 1.5❄11 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Wausau Dwtn Airport, WI (11 mi away); precipitation: Eau Pleine Rsvr, WI (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

Wisconsin planting zones →

Questions about 54455

What planting zone is ZIP code 54455?

ZIP code 54455 (Mosinee, 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 Mosinee, WI?

The median last spring frost (32 °F) near 54455 is May 6; after May 21 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Wausau Dwtn Airport station.

When is the first frost in Mosinee, WI?

The median first fall frost near 54455 is October 4, giving a median frost-free growing season of 150 days.

When should I plant tomatoes in 54455?

Start tomato seeds indoors around Mar 11 – Mar 25 and set transplants outside around May 13 – May 27, one to three weeks after the median last frost.

How much rain and snow does 54455 get?

About 34.1 inches of precipitation a year and 54 inches of snowfall (NOAA 1991–2020 normals, Eau Pleine Rsvr station).

How hot do summers get in Mosinee, WI?

The average high peaks at 80 °F in July, with about 5 days a year at 90 °F or more.

What kind of soil does 54455 have?

The USDA soil survey maps Mosinee at the center of ZIP 54455: sandy loam, well drained, pH about 5.9 (moderately acidic).

Did spring come early in Mosinee, WI in 2026?

Spring leaf-out near 54455 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 Mosinee, WI?

Long-day onions: the longest day near 54455 is 15 h 35 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 54455 change?

Yes. The 2012 USDA map put 54455 in zone 4b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.