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

Planting zone for 53588 — Spring Green, WI

ZIP code 53588 (Spring Green, Sauk County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is April 30 and the first fall frost October 9.

Where ZIP 53588 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 frostApr 30
First frostOct 9
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 Spring Green, 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 Spring Green, WI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 30median — 50% chance of a later frost
Safe for tender plantsMay 14only 10% chance of frost after
First fall frostOctober 9median — 10% chance by Sep 25
Growing season161 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 19 and returns around October 18.

From the NOAA station Lone Rock Tri Co. Airport, WI — 6 miles away, elevation 719 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 53588

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 19 – Apr 2
SpinachSow outdoors · Mar 19 – Apr 9
Broccoli, cabbageStart indoors · Feb 19 – Mar 5
Broccoli, cabbageTransplant · Apr 9 – Apr 23
Onion setsPlant outdoors · Apr 2 – Apr 16
PotatoesPlant outdoors · Apr 9 – Apr 23
LettuceSow outdoors · Apr 2 – Apr 16
Carrots, beetsSow outdoors · Apr 9 – Apr 23
TomatoesStart indoors · Mar 5 – Mar 19
TomatoesTransplant · May 7 – May 21
Peppers, eggplantStart indoors · Feb 19 – Mar 5
Peppers, eggplantTransplant · May 14 – May 28
BeansSow outdoors · May 7 – May 21
Sweet cornSow outdoors · May 7 – May 21
Cucumbers, squashSow outdoors · May 7 – May 21
Fall lettuce, spinachSow outdoors · Aug 14 – Aug 28
GarlicPlant cloves · Sep 25 – Oct 30
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 30) and first fall frost (Oct 9) 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 53588 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 Spring Green, WI.

Soil in Spring Green, WI

The soil mapped at the center of ZIP 53588 is Gotham — loamy sand, somewhat excessively drained.

TextureLoamy sanddrains and warms fast; dries out and needs more feeding
pH6.5neutral; most vegetables like 6.0–7.0
DrainageSomewhat excessively drainednatural drainage class
Organic matter1.25%low — add compost
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Gotham loamy sand, 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 53588; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Spring Green, WI

Summer high83 °Faverage high, July
Winter low10 °Faverage low, January
Hot days12days a year at 90 °F or more
Freezing nights151nights a year at 32 °F or less
Growing degree days2,745base 50 °F — the season’s usable heat
Longest day15 h 23 mindaylight on June 21
Shortest day8 h 59 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

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 28 °F, low 10 °F 28°10° JanFebruary: average high 32 °F, low 14 °F 32°14° FebMarch: average high 45 °F, low 26 °F 45°26° MarApril: average high 58 °F, low 36 °F 58°36° AprMay: average high 70 °F, low 48 °F 70°48° MayJune: average high 79 °F, low 58 °F 79°58° JunJuly: average high 83 °F, low 61 °F 83°61° JulAugust: average high 81 °F, low 59 °F 81°59° AugSeptember: average high 74 °F, low 51 °F 74°51° SepOctober: average high 61 °F, low 39 °F 61°39° OctNovember: average high 46 °F, low 28 °F 46°28° NovDecember: average high 33 °F, low 17 °F 33°17° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 0.88 in precipitation 0.9 JanFebruary: 0.87 in precipitation 0.9 FebMarch: 1.88 in precipitation 1.9 MarApril: 3.69 in precipitation 3.7 AprMay: 3.72 in precipitation 3.7 MayJune: 5.28 in precipitation 5.3 JunJuly: 4.54 in precipitation 4.5 JulAugust: 4.17 in precipitation 4.2 AugSeptember: 3.42 in precipitation 3.4 SepOctober: 2.48 in precipitation 2.5 OctNovember: 1.95 in precipitation 1.9 NovDecember: 1.20 in precipitation 1.2 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Lone Rock Tri Co. Airport, WI (6 mi away); precipitation: Lone Rock Tri Co. Airport, WI (6 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.

535035a
Arena, WI · 7 mi
535775a
Plain, WI · 8 mi
535565a
Lone Rock, WI · 9 mi
535065a
Avoca, WI · 11 mi
535844b
Sextonville, WI · 12 mi
535825a
Ridgeway, WI · 13 mi
539435a
Loganville, WI · 14 mi
535335a
Dodgeville, WI · 14 mi

Wisconsin planting zones →

Questions about 53588

What planting zone is ZIP code 53588?

ZIP code 53588 (Spring Green, 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 Spring Green, WI?

The median last spring frost (32 °F) near 53588 is April 30; after May 14 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Lone Rock Tri Co. Airport station.

When is the first frost in Spring Green, WI?

The median first fall frost near 53588 is October 9, giving a median frost-free growing season of 161 days.

When should I plant tomatoes in 53588?

Start tomato seeds indoors around Mar 5 – Mar 19 and set transplants outside around May 7 – May 21, one to three weeks after the median last frost.

How much rain and snow does 53588 get?

About 34.1 inches of precipitation a year (NOAA 1991–2020 normals, Lone Rock Tri Co. Airport station).

How hot do summers get in Spring Green, WI?

The average high peaks at 83 °F in July, with about 12 days a year at 90 °F or more.

What kind of soil does 53588 have?

The USDA soil survey maps Gotham at the center of ZIP 53588: loamy sand, somewhat excessively drained, pH about 6.5 (neutral).

Did spring come early in Spring Green, WI in 2026?

Spring leaf-out near 53588 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 Spring Green, WI?

Long-day onions: the longest day near 53588 is 15 h 23 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 53588 change?

Yes. The 2012 USDA map put 53588 in zone 4b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.