Frost Dates for Every US City
Published: February 1, 2026 · Updated: April 23, 2026
Find the last spring frost date and first fall frost date for your city. Essential for planning when to plant, when to overseed your lawn, and when to apply winteriser fertiliser.
Frost Dates by USDA Zone
| Zone | Last Spring Frost | First Fall Frost | Frost-Free Days |
|---|---|---|---|
| 3b | May 25 | September 1 | 99 days |
| 4a | May 15 | September 15 | 123 days |
| 4b | May 7 | October 1 | 147 days |
| 5a | April 15 | October 15 | 183 days |
| 5b | April 7 | October 22 | 198 days |
| 6a | March 30 | November 1 | 216 days |
| 6b | March 22 | November 10 | 233 days |
| 7a | March 15 | November 15 | 245 days |
| 7b | March 1 | November 22 | 266 days |
| 8a | February 15 | December 1 | 289 days |
| 8b | February 1 | December 15 | 317 days |
| 9a | January 30 | December 15 | 319 days |
| 9b | January 15 | December 31 | 350 days |
| 10b | Frost-free | Frost-free | 365 days |
| 12a | Frost-free | Frost-free | 365 days |
Why Frost Dates Matter for Your Lawn
Last Spring Frost signals:
- Warm-season grasses begin greening up 2–3 weeks after
- First spring fertiliser: apply when soil reaches 55°F
- Crabgrass pre-emergent: apply 2–4 weeks before last frost
First Fall Frost signals:
- Overseed window closes 6 weeks before first frost
- Apply winteriser 2–3 weeks before first frost
- Warm-season grasses stop growth 2–3 weeks after first frost
Find Your City's Frost Dates
Frequently Asked Questions
What is the last frost date in my city?
The last spring frost date is the average date of the final frost. Find your city using the state links above. These are averages — actual frost can occur 2 weeks earlier or later.
How do frost dates affect lawn care?
The last spring frost signals when to start spring lawn care. The first fall frost sets deadlines for overseeding (6 weeks before) and winteriser (2–3 weeks before).
Are frost dates the same every year?
No — they are long-term averages. Actual frost can occur 2–3 weeks earlier or later. Always monitor local weather forecasts as dates approach.
What is a USDA hardiness zone?
Zones defined by average minimum winter temperatures. They determine which plants and grasses survive winter. Most continental US is zones 3–10.
How do I protect my lawn from frost?
Apply winteriser fertiliser before the first fall frost. Avoid mowing within 48 hours of frost. Warm-season grasses going dormant after frost is normal, not damage.