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

Planting zone for Oshkosh, WI

Oshkosh, WI is in USDA zone 5b across its 5 ZIP codes. The median last spring frost is April 24 and the first fall frost October 20.

Oshkosh on the zone map

Outlined: its 3 ZIP code areas · 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
ZIP codes5
Last frostApr 24
First frostOct 20
Growing season178 days

5b 5 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Oshkosh, 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 Oshkosh, WI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 24median — 50% chance of a later frost
Safe for tender plantsMay 8only 10% chance of frost after
First fall frostOctober 20median — 10% chance by Oct 4
Growing season178 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 13 and returns around October 31.

From the NOAA station Oshkosh, WI, elevation 751 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 Oshkosh

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 13 – Mar 27
SpinachSow outdoors · Mar 13 – Apr 3
Broccoli, cabbageStart indoors · Feb 13 – Feb 27
Broccoli, cabbageTransplant · Apr 3 – Apr 17
Onion setsPlant outdoors · Mar 27 – Apr 10
PotatoesPlant outdoors · Apr 3 – Apr 17
LettuceSow outdoors · Mar 27 – Apr 10
Carrots, beetsSow outdoors · Apr 3 – Apr 17
TomatoesStart indoors · Feb 27 – Mar 13
TomatoesTransplant · May 1 – May 15
Peppers, eggplantStart indoors · Feb 13 – Feb 27
Peppers, eggplantTransplant · May 8 – May 22
BeansSow outdoors · May 1 – May 15
Sweet cornSow outdoors · May 1 – May 15
Cucumbers, squashSow outdoors · May 1 – May 15
Fall lettuce, spinachSow outdoors · Aug 25 – Sep 8
GarlicPlant cloves · Oct 6 – Nov 10
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 24) and first fall frost (Oct 20) 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 54904 came on Apr 11 — 5 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).

Native plants for zone 5b in Wisconsin

518 plants native to the lower 48 states, recorded in Wisconsin, and rated by the USDA to survive −15 °F or colder — the bottom of zone 5b. Each links to its USDA PLANTS profile.

Trees 49

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 197

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 159

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 Oshkosh, WI.

Soil in Oshkosh, WI

The soil mapped at the center of ZIP 54904 is Lorenzo variant — loam, moderately well drained.

TextureLoama good balance for most vegetables
pH7.0neutral; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter4%moderate
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Lorenzo variant loam, 2 to 8 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 54904; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Oshkosh, WI

Summer high82 °Faverage high, July
Winter low10 °Faverage low, January
Hot days8days a year at 90 °F or more
Freezing nights143nights a year at 32 °F or less
Growing degree days2,699base 50 °F — the season’s usable heat
Longest day15 h 29 mindaylight on June 21
Shortest day8 h 53 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation33.3 inper year, rain and melted snow
Snowfall39 inper year; 77 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 10 °F 26°10° JanFebruary: average high 30 °F, low 13 °F 30°13° FebMarch: average high 41 °F, low 24 °F 41°24° MarApril: average high 54 °F, low 36 °F 54°36° AprMay: average high 67 °F, low 48 °F 67°48° MayJune: average high 77 °F, low 59 °F 77°59° JunJuly: average high 82 °F, low 63 °F 82°63° JulAugust: average high 80 °F, low 61 °F 80°61° AugSeptember: average high 73 °F, low 53 °F 73°53° SepOctober: average high 59 °F, low 41 °F 59°41° OctNovember: average high 44 °F, low 29 °F 44°29° NovDecember: average high 32 °F, low 18 °F 32°18° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″January: 1.34 in precipitation, 9.8 in snowfall 1.3❄10 JanFebruary: 1.11 in precipitation, 10.1 in snowfall 1.1❄10 FebMarch: 1.92 in precipitation, 5.4 in snowfall 1.9❄5 MarApril: 3.21 in precipitation, 1.8 in snowfall 3.2❄2 AprMay: 3.94 in precipitation 3.9 MayJune: 4.82 in precipitation 4.8 JunJuly: 3.76 in precipitation 3.8 JulAugust: 3.40 in precipitation 3.4 AugSeptember: 3.26 in precipitation 3.3 SepOctober: 2.89 in precipitation, 0.3 in snowfall 2.9 OctNovember: 2.05 in precipitation, 1.8 in snowfall 2.0❄2 NovDecember: 1.59 in precipitation, 10 in snowfall 1.6❄10 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Oshkosh, WI (3 mi away); precipitation: Oshkosh, WI (3 mi away). Daylight is calculated from latitude.

ZIP codes in Oshkosh

549015b
−15 to −10 °F
549025b
−15 to −10 °F
549035b
−15 to −10 °F
549045b
−15 to −10 °F
549065b
−15 to −10 °F

Wisconsin planting zones →

Questions about Oshkosh

What planting zone is Oshkosh, WI?

Oshkosh, WI is in USDA hardiness zone 5b on the 2023 map (5b: −15 to −10 °F).

When is the last frost in Oshkosh, WI?

The median last spring frost is April 24 and the median first fall frost is October 20 (NOAA 1991–2020 normals, Oshkosh station).

When can I plant a garden in Oshkosh, WI?

Cool-season crops like peas and spinach go in around Mar 13 – Apr 3; tomatoes, peppers, beans and squash after about May 1, once frost risk has passed.

What kind of onions grow in Oshkosh, WI?

Long-day onions: the longest day is 15 h 29 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

How much rain and snow does Oshkosh, WI get?

About 33.3 inches of precipitation a year and 39 inches of snowfall (NOAA 1991–2020 normals).