When to plant in West Allis, WI
USDA Zone 5bHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for West Allis, Wisconsin — all computed from West Allis's nearest NOAA weather station.
In zone 5b, West Allis gardeners can grow many hardy perennials, while the last and first frost still dictate the annual vegetable calendar.
Frost probability
WEST ALLIS · 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 West Allis’s own odds, recorded at WEST ALLIS.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 23 | May 8 | Apr 23 | Sep 29 | Oct 10 | Oct 24 |
| 32°F | May 12 | Apr 26 | Apr 12 | Oct 7 | Oct 22 | Nov 3 |
| 28°F | Apr 30 | Apr 14 | Apr 1 | Oct 19 | Nov 1 | Nov 14 |
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 West Allis, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 8 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.
West Allis planting FAQ
When is the last spring frost in West Allis, WI?
Plan for the last spring frost in West Allis around April 26 (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 West Allis, WI?
In West Allis, the first 32°F freeze of fall lands around October 22 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is West Allis in?
West Allis 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 West Allis?
West Allis has about 179 frost-free days — a moderate growing season — between the average last spring frost (April 26) and first fall frost (October 22).
When should I plant tomatoes in West Allis?
For West Allis, sow tomatoes indoors about March 1–March 15 and move the seedlings out around May 3, after the last spring frost.
Never miss a window in West Allis
An email when it’s time to start seeds, transplant, and sow — timed to West Allis’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Greenfield · 6 km
- Wauwatosa · 6 km
- Greendale · 8 km
- Milwaukee · 8 km
- New Berlin · 9 km
- Brookfield · 10 km
- Franklin · 14 km
- Shorewood · 15 km
Frost dates recorded at WEST ALLIS, 2 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 West Allis, WI — Frost Dates & Zone 5b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00479046. Retrieved from https://blissgarden.com/wisconsin/west-allis.