When to plant in Fitchburg, WI
USDA Zone 5bFitchburg, Wisconsin frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
Zone 5b means Fitchburg sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.
Frost probability
UW ARBORETUM - MADISON · 1991–2020The 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 Fitchburg’s own odds, recorded at UW ARBORETUM - MADISON.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 30 | May 13 | Apr 29 | Sep 17 | Oct 1 | Oct 12 |
| 32°F | May 17 | May 1 | Apr 18 | Sep 26 | Oct 9 | Oct 24 |
| 28°F | May 3 | Apr 20 | Apr 7 | Oct 5 | Oct 20 | Nov 3 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Fitchburg, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 18 km · complete 32°F normalsWhen 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.
Fitchburg planting FAQ
When is the last spring frost in Fitchburg, WI?
Plan for the last spring frost in Fitchburg around May 1 (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 Fitchburg, WI?
In Fitchburg, the first 32°F freeze of fall lands around October 9 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Fitchburg in?
Fitchburg 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 Fitchburg?
There are roughly 161 frost-free days in Fitchburg (a moderate growing season), running from the average last frost around May 1 to the first fall frost near October 9.
When should I plant tomatoes in Fitchburg?
In Fitchburg, start tomato seeds indoors around March 6–March 20, then transplant seedlings outdoors around May 8 once the danger of frost has passed.
Never miss a window in Fitchburg
An email when it’s time to start seeds, transplant, and sow — timed to Fitchburg’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reachFrost dates recorded at UW ARBORETUM - MADISON, 6 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Fitchburg, WI — Frost Dates & Zone 5b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00470273. Retrieved from https://blissgarden.com/wisconsin/fitchburg.