When to plant in Mequon, WI
USDA Zone 5bEverything below — frost dates, hardiness zone, and what to plant when in Mequon, Wisconsin — is derived from the closest NOAA station with complete climate normals.
In zone 5b, Mequon gardeners can grow many hardy perennials, while the last and first frost still dictate the annual vegetable calendar.
Frost probability
GERMANTOWN · 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 Mequon’s own odds, recorded at GERMANTOWN.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Jun 3 | May 19 | May 2 | Sep 13 | Sep 29 | Oct 11 |
| 32°F | May 25 | May 6 | Apr 22 | Sep 26 | Oct 8 | Oct 24 |
| 28°F | May 12 | Apr 24 | Apr 9 | Oct 4 | 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 Mequon, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 15 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.
Mequon planting FAQ
When is the last spring frost in Mequon, WI?
On average, the last spring frost in Mequon is around May 6 (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 Mequon, WI?
The first fall frost in Mequon typically arrives around October 8 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Mequon in?
Mequon 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 Mequon?
Mequon has about 155 frost-free days — a moderate growing season — between the average last spring frost (May 6) and first fall frost (October 8).
When should I plant tomatoes in Mequon?
For Mequon, sow tomatoes indoors about March 11–March 25 and move the seedlings out around May 13, after the last spring frost.
Never miss a window in Mequon
An email when it’s time to start seeds, transplant, and sow — timed to Mequon’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Brown Deer · 5 km
- Germantown · 9 km
- Cedarburg · 10 km
- Menomonee Falls · 10 km
- Glendale · 12 km
- Grafton · 13 km
- Whitefish Bay · 14 km
- Wauwatosa · 17 km
Frost dates recorded at GERMANTOWN, 9 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 Mequon, WI — Frost Dates & Zone 5b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00473058. Retrieved from https://blissgarden.com/wisconsin/mequon.