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

Planting zone for 53578 — Prairie Du Sac, WI

ZIP code 53578 (Prairie Du Sac, Sauk County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 4 and the first fall frost October 6.

Where ZIP 53578 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 4
First frostOct 6
2012 zone5a

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 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Prairie Du Sac, 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 Prairie Du Sac, WI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 4median — 50% chance of a later frost
Safe for tender plantsMay 18only 10% chance of frost after
First fall frostOctober 6median — 10% chance by Sep 23
Growing season155 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 23 and returns around October 19.

From the NOAA station Sauk City Wwtp, WI — 4 miles away, elevation 751 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 53578

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 23 – Apr 6
SpinachSow outdoors · Mar 23 – Apr 13
Broccoli, cabbageStart indoors · Feb 23 – Mar 9
Broccoli, cabbageTransplant · Apr 13 – Apr 27
Onion setsPlant outdoors · Apr 6 – Apr 20
PotatoesPlant outdoors · Apr 13 – Apr 27
LettuceSow outdoors · Apr 6 – Apr 20
Carrots, beetsSow outdoors · Apr 13 – Apr 27
TomatoesStart indoors · Mar 9 – Mar 23
TomatoesTransplant · May 11 – May 25
Peppers, eggplantStart indoors · Feb 23 – Mar 9
Peppers, eggplantTransplant · May 18 – Jun 1
BeansSow outdoors · May 11 – May 25
Sweet cornSow outdoors · May 11 – May 25
Cucumbers, squashSow outdoors · May 11 – May 25
Fall lettuce, spinachSow outdoors · Aug 11 – Aug 25
GarlicPlant cloves · Sep 22 – Oct 27
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 4) and first fall frost (Oct 6) 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 53578 came on Mar 30 — 14 days earlier than the 1991–2020 average (Apr 13).

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 Prairie Du Sac, WI.

Soil in Prairie Du Sac, WI

The soil mapped at the center of ZIP 53578 is Dickinson — sandy loam, somewhat excessively drained.

TextureSandy loamdrains and warms fast; dries out and needs more feeding
pH6.5neutral; most vegetables like 6.0–7.0
DrainageSomewhat excessively drainednatural drainage class
Organic matter1.5%low — add compost
Hydrologic groupAwater soaks in fast
Farmland classprime farmlandUSDA classification

Map unit: Dickinson sandy loam, 1 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 53578; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Prairie Du Sac, WI

Summer high82 °Faverage high, July
Winter low8 °Faverage low, January
Hot days9days a year at 90 °F or more
Freezing nights160nights a year at 32 °F or less
Growing degree days2,523base 50 °F — the season’s usable heat
Longest day15 h 24 mindaylight on June 21
Shortest day8 h 58 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation36.5 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 27 °F, low 8 °F 27°8° JanFebruary: average high 31 °F, low 11 °F 31°11° FebMarch: average high 44 °F, low 23 °F 44°23° MarApril: average high 57 °F, low 34 °F 57°34° AprMay: average high 69 °F, low 46 °F 69°46° MayJune: average high 79 °F, low 56 °F 79°56° JunJuly: average high 82 °F, low 59 °F 82°59° JulAugust: average high 80 °F, low 58 °F 80°58° AugSeptember: average high 74 °F, low 49 °F 74°49° SepOctober: average high 61 °F, low 38 °F 61°38° OctNovember: average high 45 °F, low 26 °F 45°26° NovDecember: average high 33 °F, low 15 °F 33°15° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 1.30 in precipitation 1.3 JanFebruary: 1.33 in precipitation 1.3 FebMarch: 1.93 in precipitation 1.9 MarApril: 3.86 in precipitation 3.9 AprMay: 4.33 in precipitation 4.3 MayJune: 5.32 in precipitation 5.3 JunJuly: 4.24 in precipitation 4.2 JulAugust: 4.12 in precipitation 4.1 AugSeptember: 3.94 in precipitation 3.9 SepOctober: 2.38 in precipitation 2.4 OctNovember: 2.23 in precipitation 2.2 NovDecember: 1.54 in precipitation 1.5 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Sauk City Wwtp, WI (4 mi away); precipitation: Sauk City Wwtp, WI (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5a.

535835a
Sauk City, WI · 5 mi
539515a
North Freedom, WI · 8 mi
535605a
Mazomanie, WI · 8 mi
535615a
Merrimac, WI · 8 mi
535555a
Lodi, WI · 11 mi
539585a
Reedsburg, WI · 11 mi
539135a
Baraboo, WI · 13 mi
535295a
Dane, WI · 13 mi

Wisconsin planting zones →

Questions about 53578

What planting zone is ZIP code 53578?

ZIP code 53578 (Prairie Du Sac, 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 Prairie Du Sac, WI?

The median last spring frost (32 °F) near 53578 is May 4; after May 18 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Sauk City Wwtp station.

When is the first frost in Prairie Du Sac, WI?

The median first fall frost near 53578 is October 6, giving a median frost-free growing season of 155 days.

When should I plant tomatoes in 53578?

Start tomato seeds indoors around Mar 9 – Mar 23 and set transplants outside around May 11 – May 25, one to three weeks after the median last frost.

How much rain and snow does 53578 get?

About 36.5 inches of precipitation a year (NOAA 1991–2020 normals, Sauk City Wwtp station).

How hot do summers get in Prairie Du Sac, WI?

The average high peaks at 82 °F in July, with about 9 days a year at 90 °F or more.

What kind of soil does 53578 have?

The USDA soil survey maps Dickinson at the center of ZIP 53578: sandy loam, somewhat excessively drained, pH about 6.5 (neutral).

Did spring come early in Prairie Du Sac, WI in 2026?

Spring leaf-out near 53578 came on Mar 30 in 2026, 14 days earlier than the 1991–2020 average (Apr 13), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Prairie Du Sac, WI?

Long-day onions: the longest day near 53578 is 15 h 24 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).