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When to plant in Oshkosh, WI

USDA Zone 5b

Here are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Oshkosh, Wisconsin — all computed from Oshkosh's nearest NOAA weather station.

Zone 5b means Oshkosh sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.

Station · OSHKOSH · 0.5 km
Last spring frost
April 24
50% chance · 32°F
First fall frost
October 20
50% chance · 32°F
Growing season
179 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for OshkoshA year-band showing 32°F frost risk from January to December for Oshkosh: last spring frost around April 24, first fall frost around October 20, about 179 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

The average first fall frost in Oshkosh is now 6 days later than in the 1981–2010 normals. See how frost dates are shifting nationwide →

Frost probability

OSHKOSH · 1991–2020

The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Oshkosh’s own odds, recorded at OSHKOSH.

Frost-probability curves for OshkoshProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around April 24 and the first fall frost around October 20, giving about 179 frost-free days.
Last spring frostFirst fall frostbold = 32°F · thin = 28°F / 36°F · dot = 50% date · band = 10–90% window
ThresholdSPRING 10%SPRING 50%SPRING 90%FALL 10%FALL 50%FALL 90%
36°FMay 19May 4Apr 20Sep 24Oct 6Oct 22
32°FMay 8Apr 24Apr 10Oct 4Oct 20Nov 2
28°FApr 26Apr 13Mar 31Oct 17Oct 31Nov 13

Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.

What to plant now

TODAY · JULY 19
Fall sowopen now
Rutabaga
July 14July 28
Fall sowin 9 days
Broccoli
July 28August 11
Fall sowin 9 days
Cabbage
July 28August 11
Fall sowin 9 days
Carrot
July 28August 11
Fall sowin 9 days
Cauliflower
July 28August 11
Fall sowin 9 days
Napa Cabbage
July 28August 25
Fall sowin 23 days
Beet
August 11August 25
Fall sowin 23 days
Collards
August 11September 8
Fall sowin 23 days
Endive
August 11August 25
Fall sowin 23 days
Escarole
August 11August 25
Fall sowin 23 days
Fennel (Bulb)
August 11August 25
Fall sowin 23 days
Kale
August 11September 8
Fall sowin 23 days
Kohlrabi
August 11September 8
Fall sowin 23 days
Peas
August 11August 25
Fall sowin 23 days
Radicchio
August 11August 25
Fall sowin 23 days
Swiss Chard
August 11August 25
Fall sowin 23 days
Turnip
August 11September 8

Add these crops to your calendar (.ics) ↓

Full-year planting calendar

Start indoorsTransplantDirect sowFall sow

Each bar is the exact window to take a planting action in Oshkosh, drawn to the day from the local frost dates. The dashed line is today.

Nearby weather stations

3 within 21 km · complete 32°F normals

When stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.

OSHKOSH
Primary
0 km · 229 m elevation
SPRING
Apr 24
FALL
Oct 20
OSHKOSH WITTMAN AP
4 km · 238 m elevation
SPRING
Apr 30
FALL
Oct 13
RIPON 5 NE
21 km · 284 m elevation
SPRING
May 1
FALL
Oct 11

Oshkosh planting FAQ

When is the last spring frost in Oshkosh, WI?

Plan for the last spring frost in Oshkosh around April 24 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.

When is the first fall frost in Oshkosh, WI?

In Oshkosh, the first 32°F freeze of fall lands around October 20 on average. Time your last harvests and any season-extension cover before it.

What hardiness zone is Oshkosh in?

Oshkosh is in USDA hardiness zone 5b. In zone 5b, winters are cold — pick cold-hardy varieties and protect tender crops.

How long is the growing season in Oshkosh?

There are roughly 179 frost-free days in Oshkosh (a moderate growing season), running from the average last frost around April 24 to the first fall frost near October 20.

When should I plant tomatoes in Oshkosh?

In Oshkosh, start tomato seeds indoors around February 27–March 13, then transplant seedlings outdoors around May 1 once the danger of frost has passed.

Planting reminders

Never miss a window in Oshkosh

An email when it’s time to start seeds, transplant, and sow — timed to Oshkosh’s frost dates. Double opt-in, one-click unsubscribe, no spam.

Nearby cities

8 within reach

Frost dates recorded at OSHKOSH, 0 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.

Cite this page
BlissGarden. "When to Plant in Oshkosh, WI — Frost Dates & Zone 5b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00476330. Retrieved from https://blissgarden.com/wisconsin/oshkosh.
When to Plant in Oshkosh, WI — Frost Dates & Zone 5b — BlissGarden