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

Planting zone for 54634 — Hillsboro, WI

ZIP code 54634 (Hillsboro, Vernon County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is May 12 and the first fall frost September 29.

Where ZIP 54634 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 12
First frostSep 29
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 Hillsboro, 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 Hillsboro, WI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 12median — 50% chance of a later frost
Safe for tender plantsMay 26only 10% chance of frost after
First fall frostSeptember 29median — 10% chance by Sep 17
Growing season138 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 1 and returns around October 8.

From the NOAA station Hillsboro 2sw, WI — 4 miles away, elevation 1,043 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 54634

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 31 – Apr 14
SpinachSow outdoors · Mar 31 – Apr 21
Broccoli, cabbageStart indoors · Mar 3 – Mar 17
Broccoli, cabbageTransplant · Apr 21 – May 5
Onion setsPlant outdoors · Apr 14 – Apr 28
PotatoesPlant outdoors · Apr 21 – May 5
LettuceSow outdoors · Apr 14 – Apr 28
Carrots, beetsSow outdoors · Apr 21 – May 5
TomatoesStart indoors · Mar 17 – Mar 31
TomatoesTransplant · May 19 – Jun 2
Peppers, eggplantStart indoors · Mar 3 – Mar 17
Peppers, eggplantTransplant · May 26 – Jun 9
BeansSow outdoors · May 19 – Jun 2
Sweet cornSow outdoors · May 19 – Jun 2
Cucumbers, squashSow outdoors · May 19 – Jun 2
Fall lettuce, spinachSow outdoors · Aug 4 – Aug 18
GarlicPlant cloves · Sep 15 – Oct 20
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 12) and first fall frost (Sep 29) 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 54634 came on Mar 30 — 16 days earlier than the 1991–2020 average (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 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 Hillsboro, WI.

Soil in Hillsboro, WI

The soil mapped at the center of ZIP 54634 is Newglarus — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH6.2slightly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.5%low — add compost
Hydrologic groupCwater soaks in slowly
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Newglarus silt loam, deep, 6 to 12 percent slopes, moderately eroded.

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 54634; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Hillsboro, WI

Summer high80 °Faverage high, July
Winter low6 °Faverage low, January
Hot days2days a year at 90 °F or more
Freezing nights181nights a year at 32 °F or less
Growing degree days2,140base 50 °F — the season’s usable heat
Longest day15 h 26 mindaylight on June 21
Shortest day8 h 56 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation36.2 inper year, rain and melted snow

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 25 °F, low 6 °F 25°6° JanFebruary: average high 29 °F, low 8 °F 29°8° FebMarch: average high 41 °F, low 20 °F 41°20° MarApril: average high 55 °F, low 32 °F 55°32° AprMay: average high 66 °F, low 44 °F 66°44° MayJune: average high 76 °F, low 54 °F 76°54° JunJuly: average high 80 °F, low 57 °F 80°57° JulAugust: average high 78 °F, low 55 °F 78°55° AugSeptember: average high 71 °F, low 46 °F 71°46° SepOctober: average high 58 °F, low 36 °F 58°36° OctNovember: average high 43 °F, low 25 °F 43°25° NovDecember: average high 30 °F, low 13 °F 30°13° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 1.16 in precipitation 1.2 JanFebruary: 1.05 in precipitation 1.1 FebMarch: 1.94 in precipitation 1.9 MarApril: 3.74 in precipitation 3.7 AprMay: 4.35 in precipitation 4.3 MayJune: 5.02 in precipitation 5.0 JunJuly: 4.41 in precipitation 4.4 JulAugust: 4.40 in precipitation 4.4 AugSeptember: 3.83 in precipitation 3.8 SepOctober: 2.76 in precipitation 2.8 OctNovember: 1.99 in precipitation 2.0 NovDecember: 1.57 in precipitation 1.6 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Hillsboro 2sw, WI (4 mi away); precipitation: Hillsboro 2sw, WI (4 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.

546394b
La Farge, WI · 9 mi
539685a
Wonewoc, WI · 10 mi
539245a
Cazenovia, WI · 11 mi
539624b
Union Center, WI · 11 mi
546514b
Ontario, WI · 12 mi
546645a
Viola, WI · 13 mi
539295a
Elroy, WI · 14 mi
546385a
Kendall, WI · 14 mi

Wisconsin planting zones →

Questions about 54634

What planting zone is ZIP code 54634?

ZIP code 54634 (Hillsboro, 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 Hillsboro, WI?

The median last spring frost (32 °F) near 54634 is May 12; after May 26 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Hillsboro 2sw station.

When is the first frost in Hillsboro, WI?

The median first fall frost near 54634 is September 29, giving a median frost-free growing season of 138 days.

When should I plant tomatoes in 54634?

Start tomato seeds indoors around Mar 17 – Mar 31 and set transplants outside around May 19 – Jun 2, one to three weeks after the median last frost.

How much rain and snow does 54634 get?

About 36.2 inches of precipitation a year (NOAA 1991–2020 normals, Hillsboro 2sw station).

How hot do summers get in Hillsboro, WI?

The average high peaks at 80 °F in July, with about 2 days a year at 90 °F or more.

What kind of soil does 54634 have?

The USDA soil survey maps Newglarus at the center of ZIP 54634: silt loam, well drained, pH about 6.2 (slightly acidic).

Did spring come early in Hillsboro, WI in 2026?

Spring leaf-out near 54634 came on Mar 30 in 2026, 16 days earlier than the 1991–2020 average (Apr 15), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Hillsboro, WI?

Long-day onions: the longest day near 54634 is 15 h 26 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).