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

Planting zone for 54664 — Viola, WI

ZIP code 54664 (Viola, Vernon County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 7 and the first fall frost October 2.

Where ZIP 54664 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 7
First frostOct 2
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 Viola, 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 Viola, WI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 7median — 50% chance of a later frost
Safe for tender plantsMay 21only 10% chance of frost after
First fall frostOctober 2median — 10% chance by Sep 18
Growing season148 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 27 and returns around October 13.

From the NOAA station Viroqua, WI — 12 miles away, elevation 1,257 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 54664

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 26 – Apr 9
SpinachSow outdoors · Mar 26 – Apr 16
Broccoli, cabbageStart indoors · Feb 26 – Mar 12
Broccoli, cabbageTransplant · Apr 16 – Apr 30
Onion setsPlant outdoors · Apr 9 – Apr 23
PotatoesPlant outdoors · Apr 16 – Apr 30
LettuceSow outdoors · Apr 9 – Apr 23
Carrots, beetsSow outdoors · Apr 16 – Apr 30
TomatoesStart indoors · Mar 12 – Mar 26
TomatoesTransplant · May 14 – May 28
Peppers, eggplantStart indoors · Feb 26 – Mar 12
Peppers, eggplantTransplant · May 21 – Jun 4
BeansSow outdoors · May 14 – May 28
Sweet cornSow outdoors · May 14 – May 28
Cucumbers, squashSow outdoors · May 14 – May 28
Fall lettuce, spinachSow outdoors · Aug 7 – Aug 21
GarlicPlant cloves · Sep 18 – Oct 23
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 7) and first fall frost (Oct 2) 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 54664 came on Mar 30 — 15 days earlier than the 1991–2020 average (Apr 14).

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

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 93

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 191

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 158

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 5

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 °Fsummer grape30 ft · blooms late spring · low shade tolerance · to −23 °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 Viola, WI.

Soil in Viola, WI

The soil mapped at the center of ZIP 54664 is Fivepoints — 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 groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Fivepoints silt loam, 12 to 20 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 54664; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Viola, WI

Summer high79 °Faverage high, July
Winter low6 °Faverage low, January
Hot days3days a year at 90 °F or more
Freezing nights165nights a year at 32 °F or less
Growing degree days2,227base 50 °F — the season’s usable heat
Longest day15 h 25 mindaylight on June 21
Shortest day8 h 57 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation38.8 inper year, rain and melted snow
Snowfall46 inper year; 59 days with snow on the ground

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 23 °F, low 6 °F 23°6° JanFebruary: average high 28 °F, low 10 °F 28°10° FebMarch: average high 40 °F, low 21 °F 40°21° MarApril: average high 54 °F, low 33 °F 54°33° AprMay: average high 66 °F, low 45 °F 66°45° MayJune: average high 75 °F, low 55 °F 75°55° JunJuly: average high 79 °F, low 59 °F 79°59° JulAugust: average high 77 °F, low 57 °F 77°57° AugSeptember: average high 70 °F, low 48 °F 70°48° SepOctober: average high 57 °F, low 36 °F 57°36° OctNovember: average high 41 °F, low 24 °F 41°24° NovDecember: average high 28 °F, low 13 °F 28°13° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″6″January: 1.27 in precipitation, 11.9 in snowfall 1.3❄12 JanFebruary: 1.14 in precipitation, 9.9 in snowfall 1.1❄10 FebMarch: 2.00 in precipitation, 6.4 in snowfall 2.0❄6 MarApril: 4.01 in precipitation, 3 in snowfall 4.0❄3 AprMay: 4.89 in precipitation 4.9 MayJune: 5.39 in precipitation 5.4 JunJuly: 4.85 in precipitation 4.8 JulAugust: 4.54 in precipitation 4.5 AugSeptember: 4.11 in precipitation 4.1 SepOctober: 2.89 in precipitation, 0.3 in snowfall 2.9 OctNovember: 2.11 in precipitation, 3.1 in snowfall 2.1❄3 NovDecember: 1.59 in precipitation, 11.6 in snowfall 1.6❄12 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Viroqua, WI (12 mi away); precipitation: La Farge, WI (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

546525a
Readstown, WI · 7 mi
546394b
La Farge, WI · 9 mi
546555a
Soldiers Grove, WI · 10 mi
546344b
Hillsboro, WI · 13 mi
535815a
Richland Center, WI · 14 mi
546655a
Viroqua, WI · 15 mi
546675a
Westby, WI · 17 mi
546514b
Ontario, WI · 17 mi

Wisconsin planting zones →

Questions about 54664

What planting zone is ZIP code 54664?

ZIP code 54664 (Viola, 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 Viola, WI?

The median last spring frost (32 °F) near 54664 is May 7; after May 21 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Viroqua station.

When is the first frost in Viola, WI?

The median first fall frost near 54664 is October 2, giving a median frost-free growing season of 148 days.

When should I plant tomatoes in 54664?

Start tomato seeds indoors around Mar 12 – Mar 26 and set transplants outside around May 14 – May 28, one to three weeks after the median last frost.

How much rain and snow does 54664 get?

About 38.8 inches of precipitation a year and 46 inches of snowfall (NOAA 1991–2020 normals, La Farge station).

How hot do summers get in Viola, WI?

The average high peaks at 79 °F in July, with about 3 days a year at 90 °F or more.

What kind of soil does 54664 have?

The USDA soil survey maps Fivepoints at the center of ZIP 54664: silt loam, well drained, pH about 6.2 (slightly acidic).

Did spring come early in Viola, WI in 2026?

Spring leaf-out near 54664 came on Mar 30 in 2026, 15 days earlier than the 1991–2020 average (Apr 14), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Viola, WI?

Long-day onions: the longest day near 54664 is 15 h 25 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 54664 change?

Yes. The 2012 USDA map put 54664 in zone 4b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.