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

Planting zone for 54025 — Somerset, WI

ZIP code 54025 (Somerset, St. Croix County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is April 22 and the first fall frost October 19.

Where ZIP 54025 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 frostApr 22
First frostOct 19
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 Somerset, 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 Somerset, WI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 22median — 50% chance of a later frost
Safe for tender plantsMay 6only 10% chance of frost after
First fall frostOctober 19median — 10% chance by Oct 3
Growing season178 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 12 and returns around October 30.

From the NOAA station Stillwater 1 Se, MN — 9 miles away, elevation 709 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 54025

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 11 – Mar 25
SpinachSow outdoors · Mar 11 – Apr 1
Broccoli, cabbageStart indoors · Feb 11 – Feb 25
Broccoli, cabbageTransplant · Apr 1 – Apr 15
Onion setsPlant outdoors · Mar 25 – Apr 8
PotatoesPlant outdoors · Apr 1 – Apr 15
LettuceSow outdoors · Mar 25 – Apr 8
Carrots, beetsSow outdoors · Apr 1 – Apr 15
TomatoesStart indoors · Feb 25 – Mar 11
TomatoesTransplant · Apr 29 – May 13
Peppers, eggplantStart indoors · Feb 11 – Feb 25
Peppers, eggplantTransplant · May 6 – May 20
BeansSow outdoors · Apr 29 – May 13
Sweet cornSow outdoors · Apr 29 – May 13
Cucumbers, squashSow outdoors · Apr 29 – May 13
Fall lettuce, spinachSow outdoors · Aug 24 – Sep 7
GarlicPlant cloves · Oct 5 – Nov 9
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 22) and first fall frost (Oct 19) 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 54025 came on Apr 11 — 7 days earlier than the 1991–2020 average (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.

Trees 48

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 89

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 178

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 152

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 4

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 °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 Somerset, WI.

Soil in Somerset, WI

The soil mapped at the center of ZIP 54025 is Plainfield — loamy sand, excessively drained.

TextureLoamy sanddrains and warms fast; dries out and needs more feeding
pH6.2slightly acidic; most vegetables like 6.0–7.0
DrainageExcessively drainednatural drainage class
Organic matter1.25%low — add compost
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Plainfield loamy sand, 12 to 20 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 54025; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Somerset, WI

Summer high85 °Faverage high, July
Winter low9 °Faverage low, January
Hot days18days a year at 90 °F or more
Freezing nights147nights a year at 32 °F or less
Growing degree days3,188base 50 °F — the season’s usable heat
Longest day15 h 38 mindaylight on June 21
Shortest day8 h 45 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation35.1 inper year, rain and melted snow

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 27 °F, low 9 °F 27°9° JanFebruary: average high 32 °F, low 14 °F 32°14° FebMarch: average high 45 °F, low 25 °F 45°25° MarApril: average high 60 °F, low 38 °F 60°38° AprMay: average high 73 °F, low 50 °F 73°50° MayJune: average high 81 °F, low 60 °F 81°60° JunJuly: average high 85 °F, low 64 °F 85°64° JulAugust: average high 84 °F, low 62 °F 84°62° AugSeptember: average high 76 °F, low 55 °F 76°55° SepOctober: average high 62 °F, low 42 °F 62°42° OctNovember: average high 45 °F, low 28 °F 45°28° NovDecember: average high 32 °F, low 16 °F 32°16° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 0.98 in precipitation 1.0 JanFebruary: 0.93 in precipitation 0.9 FebMarch: 1.47 in precipitation 1.5 MarApril: 3.11 in precipitation 3.1 AprMay: 4.23 in precipitation 4.2 MayJune: 5.36 in precipitation 5.4 JunJuly: 4.54 in precipitation 4.5 JulAugust: 5.29 in precipitation 5.3 AugSeptember: 3.19 in precipitation 3.2 SepOctober: 3.16 in precipitation 3.2 OctNovember: 1.65 in precipitation 1.6 NovDecember: 1.15 in precipitation 1.1 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Stillwater 1 Se, MN (9 mi away); precipitation: Stillwater 1 Se, MN (9 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.

540824b
Houlton, WI · 6 mi
550474b
Marine On Saint Croix, MN · 8 mi
540174b
New Richmond, WI · 8 mi
540204b
Osceola, WI · 9 mi
540264b
Star Prairie, WI · 9 mi
550824b
Stillwater, MN · 9 mi
550035a
Bayport, MN · 11 mi
540164b
Hudson, WI · 11 mi

Wisconsin planting zones →

Questions about 54025

What planting zone is ZIP code 54025?

ZIP code 54025 (Somerset, 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 Somerset, WI?

The median last spring frost (32 °F) near 54025 is April 22; after May 6 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Stillwater 1 Se station.

When is the first frost in Somerset, WI?

The median first fall frost near 54025 is October 19, giving a median frost-free growing season of 178 days.

When should I plant tomatoes in 54025?

Start tomato seeds indoors around Feb 25 – Mar 11 and set transplants outside around Apr 29 – May 13, one to three weeks after the median last frost.

How much rain and snow does 54025 get?

About 35.1 inches of precipitation a year (NOAA 1991–2020 normals, Stillwater 1 Se station).

How hot do summers get in Somerset, WI?

The average high peaks at 85 °F in July, with about 18 days a year at 90 °F or more.

What kind of soil does 54025 have?

The USDA soil survey maps Plainfield at the center of ZIP 54025: loamy sand, excessively drained, pH about 6.2 (slightly acidic).

Did spring come early in Somerset, WI in 2026?

Spring leaf-out near 54025 came on Apr 11 in 2026, 7 days earlier than the 1991–2020 average (Apr 18), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Somerset, WI?

Long-day onions: the longest day near 54025 is 15 h 38 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).