When to plant in Waukesha, WI
USDA Zone 5bHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Waukesha, Wisconsin — all computed from Waukesha's nearest NOAA weather station.
Zone 5b means Waukesha sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.
The average first fall frost in Waukesha is now 7 days later than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
WAUKESHA WWTP · 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 Waukesha’s own odds, recorded at WAUKESHA WWTP.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 29 | May 13 | Apr 29 | Sep 20 | Oct 2 | Oct 15 |
| 32°F | May 18 | May 1 | Apr 18 | Sep 29 | Oct 13 | Oct 25 |
| 28°F | May 5 | Apr 19 | Apr 6 | Oct 8 | Oct 23 | Nov 6 |
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 Waukesha, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 19 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.
Waukesha planting FAQ
When is the last spring frost in Waukesha, WI?
Waukesha's average last spring frost falls near May 1 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.
When is the first fall frost in Waukesha, WI?
In Waukesha, the first 32°F freeze of fall lands around October 13 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Waukesha in?
Waukesha 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 Waukesha?
There are roughly 165 frost-free days in Waukesha (a moderate growing season), running from the average last frost around May 1 to the first fall frost near October 13.
When should I plant tomatoes in Waukesha?
In Waukesha, 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 Waukesha
An email when it’s time to start seeds, transplant, and sow — timed to Waukesha’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Pewaukee · 6 km
- New Berlin · 10 km
- Brookfield · 12 km
- Sussex · 14 km
- Lisbon · 17 km
- West Allis · 18 km
- Muskego · 18 km
- Wauwatosa · 18 km
Frost dates recorded at WAUKESHA WWTP, 0 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 Waukesha, WI — Frost Dates & Zone 5b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00478937. Retrieved from https://blissgarden.com/wisconsin/waukesha.