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

Planting zone for 53125 — Fontana, WI

ZIP code 53125 (Fontana, Walworth County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is April 25 and the first fall frost October 21.

Where ZIP 53125 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.

Zone5b−15 to −10 °F
Coldest night−26.1 to −23.3 °C
Last frostApr 25
First frostOct 21
2012 zone5b

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 5b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Fontana, 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 Fontana, WI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 25median — 50% chance of a later frost
Safe for tender plantsMay 10only 10% chance of frost after
First fall frostOctober 21median — 10% chance by Oct 5
Growing season179 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 12 and returns around November 1.

From the NOAA station Lake Geneva Wwtp, WI — 8 miles away, elevation 846 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 53125

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 14 – Mar 28
SpinachSow outdoors · Mar 14 – Apr 4
Broccoli, cabbageStart indoors · Feb 14 – Feb 28
Broccoli, cabbageTransplant · Apr 4 – Apr 18
Onion setsPlant outdoors · Mar 28 – Apr 11
PotatoesPlant outdoors · Apr 4 – Apr 18
LettuceSow outdoors · Mar 28 – Apr 11
Carrots, beetsSow outdoors · Apr 4 – Apr 18
TomatoesStart indoors · Feb 28 – Mar 14
TomatoesTransplant · May 2 – May 16
Peppers, eggplantStart indoors · Feb 14 – Feb 28
Peppers, eggplantTransplant · May 9 – May 23
BeansSow outdoors · May 2 – May 16
Sweet cornSow outdoors · May 2 – May 16
Cucumbers, squashSow outdoors · May 2 – May 16
Fall lettuce, spinachSow outdoors · Aug 26 – Sep 9
GarlicPlant cloves · Oct 7 – Nov 11
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 25) and first fall frost (Oct 21) 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 53125 came on Mar 30 — 12 days earlier than the 1991–2020 average (Apr 11).

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 Fontana, WI

The soil mapped at the center of ZIP 53125 is Miami — loam, well drained.

TextureLoama good balance for most vegetables
pH7.0neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2%moderate
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Miami loam, sandy loam substratum, 12 to 20 percent slopes, 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 53125; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Fontana, WI

Summer high86 °Faverage high, July
Winter low15 °Faverage low, January
Hot days21days a year at 90 °F or more
Freezing nights136nights a year at 32 °F or less
Growing degree days3,091base 50 °F — the season’s usable heat
Longest day15 h 18 mindaylight on June 21
Shortest day9 h 03 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation37 inper year, rain and melted snow
Snowfall40 inper year; 60 days with snow on the ground

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 30 °F, low 15 °F 30°15° JanFebruary: average high 35 °F, low 17 °F 35°17° FebMarch: average high 45 °F, low 26 °F 45°26° MarApril: average high 59 °F, low 37 °F 59°37° AprMay: average high 72 °F, low 48 °F 72°48° MayJune: average high 81 °F, low 58 °F 81°58° JunJuly: average high 86 °F, low 63 °F 86°63° JulAugust: average high 83 °F, low 61 °F 83°61° AugSeptember: average high 76 °F, low 54 °F 76°54° SepOctober: average high 63 °F, low 42 °F 63°42° OctNovember: average high 47 °F, low 31 °F 47°31° NovDecember: average high 35 °F, low 21 °F 35°21° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″January: 1.90 in precipitation, 13.9 in snowfall 1.9❄14 JanFebruary: 1.89 in precipitation, 8.1 in snowfall 1.9❄8 FebMarch: 2.29 in precipitation, 4.8 in snowfall 2.3❄5 MarApril: 3.45 in precipitation, 2.6 in snowfall 3.5❄3 AprMay: 4.12 in precipitation 4.1 MayJune: 4.81 in precipitation 4.8 JunJuly: 3.72 in precipitation 3.7 JulAugust: 3.32 in precipitation 3.3 AugSeptember: 3.65 in precipitation 3.6 SepOctober: 3.01 in precipitation, 0.2 in snowfall 3.0 OctNovember: 2.48 in precipitation, 3.4 in snowfall 2.5❄3 NovDecember: 2.31 in precipitation, 7.1 in snowfall 2.3❄7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Lake Geneva Wwtp, WI (8 mi away); precipitation: Lake Geneva Wwtp, WI (8 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5b.

531915b
Williams Bay, WI · 2 mi
531845b
Walworth, WI · 3 mi
531955b
Zenda, WI · 4 mi
531475b
Lake Geneva, WI · 6 mi
535855b
Sharon, WI · 8 mi
600335b
Harvard, IL · 9 mi
600345b
Hebron, IL · 9 mi
531155b
Delavan, WI · 9 mi

Wisconsin planting zones →

Questions about 53125

What planting zone is ZIP code 53125?

ZIP code 53125 (Fontana, WI) is in USDA hardiness zone 5b on the 2023 map: the coldest night of an average winter reaches −15 to −10 °F (−26.1 to −23.3 °C).

When is the last frost in Fontana, WI?

The median last spring frost (32 °F) near 53125 is April 25; after May 10 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Lake Geneva Wwtp station.

When is the first frost in Fontana, WI?

The median first fall frost near 53125 is October 21, giving a median frost-free growing season of 179 days.

When should I plant tomatoes in 53125?

Start tomato seeds indoors around Feb 28 – Mar 14 and set transplants outside around May 2 – May 16, one to three weeks after the median last frost.

How much rain and snow does 53125 get?

About 37 inches of precipitation a year and 40 inches of snowfall (NOAA 1991–2020 normals, Lake Geneva Wwtp station).

How hot do summers get in Fontana, WI?

The average high peaks at 86 °F in July, with about 21 days a year at 90 °F or more.

What kind of soil does 53125 have?

The USDA soil survey maps Miami at the center of ZIP 53125: loam, well drained, pH about 7.0 (neutral).

Did spring come early in Fontana, WI in 2026?

Spring leaf-out near 53125 came on Mar 30 in 2026, 12 days earlier than the 1991–2020 average (Apr 11), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Fontana, WI?

Long-day onions: the longest day near 53125 is 15 h 18 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).