When to plant in Oregon, WI
USDA Zone 5aHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Oregon, Wisconsin — all computed from Oregon's nearest NOAA weather station.
In zone 5a, Oregon gardeners can grow many hardy perennials, while the last and first frost still dictate the annual vegetable calendar.
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 Oregon’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 Oregon, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 17 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.
Oregon planting FAQ
When is the last spring frost in Oregon, WI?
Plan for the last spring frost in Oregon 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 Oregon, WI?
In Oregon, 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 Oregon in?
Oregon is in USDA hardiness zone 5a. In zone 5a, winters are cold — pick cold-hardy varieties and protect tender crops.
How long is the growing season in Oregon?
Oregon has about 161 frost-free days — a moderate growing season — between the average last spring frost (May 1) and first fall frost (October 9).
When should I plant tomatoes in Oregon?
For Oregon, sow tomatoes indoors about March 6–March 20 and move the seedlings out around May 8, after the last spring frost.
Never miss a window in Oregon
An email when it’s time to start seeds, transplant, and sow — timed to Oregon’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reachFrost dates recorded at UW ARBORETUM - MADISON, 13 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 Oregon, WI — Frost Dates & Zone 5a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00470273. Retrieved from https://blissgarden.com/wisconsin/oregon.