Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 53039 — Juneau, WI

ZIP code 53039 (Juneau, Dodge County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is April 28 and the first fall frost October 10.

Where ZIP 53039 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 28

First frostOct 10

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 Juneau, 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 Juneau, WI

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostApril 28median — 50% chance of a later frost

Safe for tender plantsMay 13only 10% chance of frost after

First fall frostOctober 10median — 10% chance by Sep 26

Growing season164 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 16 and returns around October 22.

From the NOAA station Hustisford Wwtp, WI — 6 miles away, elevation 863 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 53039

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 17 – Mar 31

SpinachSow outdoors · Mar 17 – Apr 7

Broccoli, cabbageStart indoors · Feb 17 – Mar 3

Broccoli, cabbageTransplant · Apr 7 – Apr 21

Onion setsPlant outdoors · Mar 31 – Apr 14

PotatoesPlant outdoors · Apr 7 – Apr 21

LettuceSow outdoors · Mar 31 – Apr 14

Carrots, beetsSow outdoors · Apr 7 – Apr 21

TomatoesStart indoors · Mar 3 – Mar 17

TomatoesTransplant · May 5 – May 19

Peppers, eggplantStart indoors · Feb 17 – Mar 3

Peppers, eggplantTransplant · May 12 – May 26

BeansSow outdoors · May 5 – May 19

Sweet cornSow outdoors · May 5 – May 19

Cucumbers, squashSow outdoors · May 5 – May 19

Fall lettuce, spinachSow outdoors · Aug 15 – Aug 29

GarlicPlant cloves · Sep 26 – Oct 31

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 28) and first fall frost (Oct 10) 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 53039 came on Mar 30 — 15 days earlier than the 1991–2020 average (Apr 14).

average
Apr 142026
Mar 30

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).

Soil in Juneau, WI

The soil mapped at the center of ZIP 53039 is Miami — clay loam, well drained.

TextureClay loamholds water and nutrients; slow to drain and warm up

pH7.0neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter0.75%low — add compost

Hydrologic groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Miami soils, 18 to 30 percent slopes, severely 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 53039; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Juneau, WI

Summer high82 °Faverage high, July

Winter low11 °Faverage low, January

Hot days8days a year at 90 °F or more

Freezing nights149nights a year at 32 °F or less

Growing degree days2,584base 50 °F — the season’s usable heat

Longest day15 h 24 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)

Precipitation35 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Hustisford Wwtp, WI (6 mi away); precipitation: Clyman, WI (4 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.

Hustisford, WI · 5 mi

Iron Ridge, WI · 8 mi

530475a

Lebanon, WI · 9 mi

539165a

Beaver Dam, WI · 9 mi

Wisconsin planting zones →

Questions about 53039

What planting zone is ZIP code 53039?

ZIP code 53039 (Juneau, 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 Juneau, WI?

The median last spring frost (32 °F) near 53039 is April 28; after May 13 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Hustisford Wwtp station.

When is the first frost in Juneau, WI?

The median first fall frost near 53039 is October 10, giving a median frost-free growing season of 164 days.

When should I plant tomatoes in 53039?

Start tomato seeds indoors around Mar 3 – Mar 17 and set transplants outside around May 5 – May 19, one to three weeks after the median last frost.

How much rain and snow does 53039 get?

About 35 inches of precipitation a year (NOAA 1991–2020 normals, Clyman station).

How hot do summers get in Juneau, WI?

The average high peaks at 82 °F in July, with about 8 days a year at 90 °F or more.

What kind of soil does 53039 have?

The USDA soil survey maps Miami at the center of ZIP 53039: clay loam, well drained, pH about 7.0 (neutral).

Did spring come early in Juneau, WI in 2026?

Spring leaf-out near 53039 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 Juneau, WI?

Long-day onions: the longest day near 53039 is 15 h 24 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).