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

Planting zone for 53940 — Lake Delton, WI

ZIP code 53940 (Lake Delton, Sauk County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 8 and the first fall frost October 3.

Where ZIP 53940 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 8
First frostOct 3
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 Lake Delton, 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 Lake Delton, WI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 8median — 50% chance of a later frost
Safe for tender plantsMay 22only 10% chance of frost after
First fall frostOctober 3median — 10% chance by Sep 21
Growing season146 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 28 and returns around October 14.

From the NOAA station Wisconsin Dells, WI — 2 miles away, elevation 837 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 53940

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 27 – Apr 10
SpinachSow outdoors · Mar 27 – Apr 17
Broccoli, cabbageStart indoors · Feb 27 – Mar 13
Broccoli, cabbageTransplant · Apr 17 – May 1
Onion setsPlant outdoors · Apr 10 – Apr 24
PotatoesPlant outdoors · Apr 17 – May 1
LettuceSow outdoors · Apr 10 – Apr 24
Carrots, beetsSow outdoors · Apr 17 – May 1
TomatoesStart indoors · Mar 13 – Mar 27
TomatoesTransplant · May 15 – May 29
Peppers, eggplantStart indoors · Feb 27 – Mar 13
Peppers, eggplantTransplant · May 22 – Jun 5
BeansSow outdoors · May 15 – May 29
Sweet cornSow outdoors · May 15 – May 29
Cucumbers, squashSow outdoors · May 15 – May 29
Fall lettuce, spinachSow outdoors · Aug 8 – Aug 22
GarlicPlant cloves · Sep 19 – Oct 24
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 8) and first fall frost (Oct 3) 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 53940 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 Lake Delton, WI.

Soil in Lake Delton, WI

The soil mapped at the center of ZIP 53940 is Boone — sand, excessively drained.

TextureSanddrains and warms fast; dries out and needs more feeding
pH5.4strongly acidic; most vegetables like 6.0–7.0
DrainageExcessively drainednatural drainage class
Organic matter0.75%low — add compost
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Boone-Elevasil complex, 15 to 45 percent slopes, rocky.

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 53940; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Lake Delton, WI

Summer high83 °Faverage high, July
Winter low8 °Faverage low, January
Hot days10days a year at 90 °F or more
Freezing nights168nights a year at 32 °F or less
Growing degree days2,517base 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)
Precipitation37.5 inper year, rain and melted snow
Snowfall41 inper year; 85 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 26 °F, low 8 °F 26°8° JanFebruary: average high 31 °F, low 11 °F 31°11° FebMarch: average high 43 °F, low 22 °F 43°22° MarApril: average high 57 °F, low 33 °F 57°33° AprMay: average high 69 °F, low 45 °F 69°45° MayJune: average high 79 °F, low 56 °F 79°56° JunJuly: average high 83 °F, low 60 °F 83°60° JulAugust: average high 81 °F, low 57 °F 81°57° AugSeptember: average high 73 °F, low 49 °F 73°49° SepOctober: average high 60 °F, low 37 °F 60°37° OctNovember: average high 44 °F, low 26 °F 44°26° NovDecember: average high 32 °F, low 15 °F 32°15° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″6″January: 1.32 in precipitation, 11.5 in snowfall 1.3❄12 JanFebruary: 1.38 in precipitation, 10.2 in snowfall 1.4❄10 FebMarch: 2.28 in precipitation, 5.9 in snowfall 2.3❄6 MarApril: 4.08 in precipitation, 2 in snowfall 4.1❄2 AprMay: 4.38 in precipitation 4.4 MayJune: 5.11 in precipitation 5.1 JunJuly: 4.04 in precipitation 4.0 JulAugust: 4.22 in precipitation 4.2 AugSeptember: 3.84 in precipitation 3.8 SepOctober: 2.82 in precipitation, 0.4 in snowfall 2.8 OctNovember: 2.23 in precipitation, 2 in snowfall 2.2❄2 NovDecember: 1.77 in precipitation, 8.7 in snowfall 1.8❄9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Wisconsin Dells, WI (2 mi away); precipitation: Wisconsin Dells, WI (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5a.

539655a
Wisconsin Dells, WI · 6 mi
539135a
Baraboo, WI · 8 mi
539445a
Lyndon Station, WI · 10 mi
539595a
Reedsburg, WI · 11 mi
539205a
Briggsville, WI · 11 mi
539615a
Rock Springs, WI · 12 mi
539515a
North Freedom, WI · 15 mi
535615a
Merrimac, WI · 15 mi

Wisconsin planting zones →

Questions about 53940

What planting zone is ZIP code 53940?

ZIP code 53940 (Lake Delton, 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 Lake Delton, WI?

The median last spring frost (32 °F) near 53940 is May 8; after May 22 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Wisconsin Dells station.

When is the first frost in Lake Delton, WI?

The median first fall frost near 53940 is October 3, giving a median frost-free growing season of 146 days.

When should I plant tomatoes in 53940?

Start tomato seeds indoors around Mar 13 – Mar 27 and set transplants outside around May 15 – May 29, one to three weeks after the median last frost.

How much rain and snow does 53940 get?

About 37.5 inches of precipitation a year and 41 inches of snowfall (NOAA 1991–2020 normals, Wisconsin Dells station).

How hot do summers get in Lake Delton, WI?

The average high peaks at 83 °F in July, with about 10 days a year at 90 °F or more.

What kind of soil does 53940 have?

The USDA soil survey maps Boone at the center of ZIP 53940: sand, excessively drained, pH about 5.4 (strongly acidic).

Did spring come early in Lake Delton, WI in 2026?

Spring leaf-out near 53940 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 Lake Delton, WI?

Long-day onions: the longest day near 53940 is 15 h 26 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).