Delaware Frost Dates
Published: February 1, 2026 · Updated: April 23, 2026
Last Spring Frost
March 30
Zone 6a
First Fall Frost
November 1
Zone 6a
Frost-Free Season
216 days
Late March to Mid-November
Lawn Care Timing for Delaware
Vegetable Garden Timing for Delaware
Frost Dates by City in Delaware
Frequently Asked Questions
What is the last frost date in Delaware?
The average last spring frost in Delaware (zone 6a) is March 30. Dates vary by city and elevation. Find your specific city below for exact dates.
When is it safe to plant tomatoes in Delaware?
Transplant tomato seedlings outdoors after March 30 — the average last frost date for zone 6a. Start seeds indoors Late January. Wait 2 weeks after last frost for extra safety.
When should I overseed my lawn in Delaware?
The prime overseeding window in Delaware is September 1–October 1. This ensures 6 weeks of warm soil for germination before the first fall frost on November 1.
When should I apply winteriser in Delaware?
Apply winteriser fertiliser by Mid-November. Your first fall frost of November 1 is the hard deadline — apply at least 2–3 weeks before.
What USDA zone is Delaware?
Delaware contains USDA zones 6a. Each zone has different frost dates and growing seasons. Find your city below for your specific zone.