Wisconsin Frost Dates
Published: February 1, 2026 · Updated: April 23, 2026
Last Spring Frost
April 7
Zone 5b
First Fall Frost
October 22
Zone 5b
Frost-Free Season
198 days
Early April to Early November
Lawn Care Timing for Wisconsin
Vegetable Garden Timing for Wisconsin
Frost Dates by City in Wisconsin
Frequently Asked Questions
What is the last frost date in Wisconsin?
The average last spring frost in Wisconsin (zone 5b) is April 7. Dates vary by city and elevation. Find your specific city below for exact dates.
When is it safe to plant tomatoes in Wisconsin?
Transplant tomato seedlings outdoors after April 7 — the average last frost date for zone 5b. Start seeds indoors Late January. Wait 2 weeks after last frost for extra safety.
When should I overseed my lawn in Wisconsin?
The prime overseeding window in Wisconsin is August 20–September 20. This ensures 6 weeks of warm soil for germination before the first fall frost on October 22.
When should I apply winteriser in Wisconsin?
Apply winteriser fertiliser by Early November. Your first fall frost of October 22 is the hard deadline — apply at least 2–3 weeks before.
What USDA zone is Wisconsin?
Wisconsin contains USDA zones 5a, 5b. Each zone has different frost dates and growing seasons. Find your city below for your specific zone.