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

Planting zone for 54941 — Green Lake, WI

ZIP code 54941 (Green Lake, Green Lake 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 2.

Where ZIP 54941 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 2
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 Green Lake, 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 Green Lake, 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 23only 10% chance of frost after
First fall frostOctober 2median — 10% chance by Sep 19
Growing season144 daysfrost-free, median

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

From the NOAA station Markesan, WI — 10 miles away, elevation 860 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 54941

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 7 – Aug 21
GarlicPlant cloves · Sep 18 – Oct 23
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 8) and first fall frost (Oct 2) 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 54941 came on Apr 10 — 6 days earlier than the 1991–2020 average (Apr 16).

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 Green Lake, WI

The soil mapped at the center of ZIP 54941 is Kidder — 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 classprime farmlandUSDA classification

Map unit: Kidder loam, 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 54941; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Green Lake, WI

Summer high82 °Faverage high, July
Winter low9 °Faverage low, January
Hot days7days a year at 90 °F or more
Freezing nights162nights a year at 32 °F or less
Growing degree days2,396base 50 °F — the season’s usable heat
Longest day15 h 28 mindaylight on June 21
Shortest day8 h 54 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation35.6 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 26 °F, low 9 °F 26°9° JanFebruary: average high 30 °F, low 10 °F 30°10° FebMarch: average high 42 °F, low 21 °F 42°21° MarApril: average high 56 °F, low 33 °F 56°33° AprMay: average high 68 °F, low 45 °F 68°45° MayJune: average high 78 °F, low 55 °F 78°55° JunJuly: average high 82 °F, low 59 °F 82°59° JulAugust: average high 80 °F, low 56 °F 80°56° AugSeptember: average high 72 °F, low 48 °F 72°48° SepOctober: average high 59 °F, low 37 °F 59°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

0″1″2″3″4″5″January: 1.38 in precipitation 1.4 JanFebruary: 1.39 in precipitation 1.4 FebMarch: 2.00 in precipitation 2.0 MarApril: 3.45 in precipitation 3.5 AprMay: 4.29 in precipitation 4.3 MayJune: 4.58 in precipitation 4.6 JunJuly: 4.29 in precipitation 4.3 JulAugust: 4.15 in precipitation 4.2 AugSeptember: 3.27 in precipitation 3.3 SepOctober: 2.93 in precipitation 2.9 OctNovember: 2.23 in precipitation 2.2 NovDecember: 1.65 in precipitation 1.6 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Markesan, WI (10 mi away); precipitation: Markesan, WI (10 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5a.

549685a
Princeton, WI · 7 mi
549715a
Ripon, WI · 8 mi
539465a
Markesan, WI · 9 mi
539315a
Fairwater, WI · 9 mi
549235a
Berlin, WI · 11 mi
539395a
Kingston, WI · 13 mi
549605a
Neshkoro, WI · 13 mi
539195a
Brandon, WI · 13 mi

Wisconsin planting zones →

Questions about 54941

What planting zone is ZIP code 54941?

ZIP code 54941 (Green Lake, 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 Green Lake, WI?

The median last spring frost (32 °F) near 54941 is May 8; after May 23 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Markesan station.

When is the first frost in Green Lake, WI?

The median first fall frost near 54941 is October 2, giving a median frost-free growing season of 144 days.

When should I plant tomatoes in 54941?

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 54941 get?

About 35.6 inches of precipitation a year (NOAA 1991–2020 normals, Markesan station).

How hot do summers get in Green Lake, WI?

The average high peaks at 82 °F in July, with about 7 days a year at 90 °F or more.

What kind of soil does 54941 have?

The USDA soil survey maps Kidder at the center of ZIP 54941: loam, well drained, pH about 7.0 (neutral).

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

Spring leaf-out near 54941 came on Apr 10 in 2026, 6 days earlier than the 1991–2020 average (Apr 16), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Green Lake, WI?

Long-day onions: the longest day near 54941 is 15 h 28 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).