When to plant in Harrison, WI
USDA Zone 5bHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Harrison, Wisconsin — all computed from Harrison's nearest NOAA weather station.
Zone 5b means Harrison sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.
Frost probability
APPLETON · 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 Harrison’s own odds, recorded at APPLETON.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 29 | May 15 | Apr 30 | Sep 15 | Sep 28 | Oct 11 |
| 32°F | May 20 | May 4 | Apr 21 | Sep 23 | Oct 6 | Oct 21 |
| 28°F | May 8 | Apr 23 | Apr 9 | Oct 1 | Oct 18 | 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 Harrison, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 21 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.
Harrison planting FAQ
When is the last spring frost in Harrison, WI?
On average, the last spring frost in Harrison is around May 4 (50% probability at 32°F, from 1991–2020 NOAA normals). Wait until after this date to set out tender plants like tomatoes and peppers.
When is the first fall frost in Harrison, WI?
Expect Harrison's first fall frost near October 6 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Harrison in?
Harrison 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 Harrison?
There are roughly 155 frost-free days in Harrison (a moderate growing season), running from the average last frost around May 4 to the first fall frost near October 6.
When should I plant tomatoes in Harrison?
In Harrison, start tomato seeds indoors around March 9–March 23, then transplant seedlings outdoors around May 11 once the danger of frost has passed.
Never miss a window in Harrison
An email when it’s time to start seeds, transplant, and sow — timed to Harrison’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Kaukauna · 10 km
- Menasha · 11 km
- Little Chute · 11 km
- Appleton · 12 km
- Neenah · 15 km
- Fox Crossing · 15 km
- Greenville · 23 km
- Oshkosh · 28 km
Frost dates recorded at APPLETON, 15 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 Harrison, WI — Frost Dates & Zone 5b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00470265. Retrieved from https://blissgarden.com/wisconsin/harrison.