Frost Dates Guide: First and Last Frost Dates Explained
Your frost dates define your entire planting schedule.
Every planting decision traces back to two numbers: your last spring frost date and your first fall frost date. These define your growing season. Understanding frost dates is the single most important skill in garden planning.
All frost date data from the Plant Anywhere frost date database, covering 9,275 US ZIP codes using 30-year NOAA climate averages.
What Are Frost Dates
Frost dates are statistical averages, not guarantees. Your last spring frost date is the date after which the probability of a killing frost drops below 50 percent, based on 30 years of weather data. Your first fall frost date is when frost becomes more likely than not.
In any given year, the actual last frost might come 2 weeks earlier or later. Experienced gardeners treat frost dates as guidelines. Waiting 1 to 2 weeks after your last frost date substantially reduces risk for warm-season transplants.
Light frost vs. hard freeze
A light frost (32 to 36 degrees F) damages tender warm-season crops but leaves cold-hardy crops unharmed. A hard freeze (below 28 degrees) damages or kills most garden plants.
How to Find Your Frost Dates
1. ZIP code lookup
Enter your ZIP code into the Plant Anywhere frost date finder for your average last spring frost, first fall frost, growing season length, and USDA zone.
2. USDA zone averages
Use the zone-level frost date averages in the table below. Less precise than ZIP-level but sufficient for planning.
3. Local extension office
Your county cooperative extension office publishes frost date information specific to your area.
Frost Dates by USDA Zone
| USDA Zone | Last Spring Frost | First Fall Frost | Growing Season (Days) |
|---|---|---|---|
| Zone 3 | May 15 | Sep 15 | 120 |
| Zone 4 | May 1 | Oct 1 | 150 |
| Zone 5 | Apr 15 | Oct 15 | 180 |
| Zone 6 | Apr 1 | Oct 31 | 210 |
| Zone 7 | Apr 15 | Oct 15 | 180 |
| Zone 8 | Mar 15 | Nov 15 | 245 |
| Zone 9 | Feb 15 | Dec 1 | 290 |
| Zone 10 | Jan 31 | Dec 15 | 320 |
How to Use Your Frost Dates
Warm-season crops
Tomatoes, peppers, squash, beans, cucumbers cannot tolerate frost. Plant 1 to 2 weeks after your last frost date. See the seed starting schedule.
Cool-season crops
Lettuce, peas, spinach, radishes, kale tolerate light frost. Plant 2 to 4 weeks before your last frost date. Plan a second planting 6 to 8 weeks before first fall frost.
Extending the Growing Season
Row covers
Floating row cover provides 2 to 8 degrees F of frost protection. Also blocks insects.
Cold frames
Bottomless box with transparent lid. Extends season 4 to 6 weeks.
Water-filled protectors
Keep plants 10 to 15 degrees warmer. Allow transplanting 3 to 4 weeks early.
Mulch
3 to 4 inches insulates soil and moderates temperature swings. See the watering guide.
Emergency Frost Protection
- Water the soil in the afternoon. Moist soil holds heat.
- Cover plants before sunset with row cover or sheets.
- Avoid plastic directly on plants.
- Remove covers in the morning above 40 degrees.
Related Guides
- How to Start a Vegetable Garden: Beginner Guide 2026
- Seed Starting Schedule 2026: When to Start Seeds Indoors by Zone
- Frost Dates Guide: How Frost Dates Work and How to Use Them
- Indoor Herb Garden: Growing Herbs Year-Round
- Raised Bed Planner: Design Your Perfect Layout
- Watering Guide: How Much Water Does Your Garden Need?
- Browse All 216 Crop Profiles
- Find Your Frost Dates by ZIP Code
Frequently Asked Questions
What is a frost date?
The average date of the last spring or first fall killing frost based on 30-year NOAA data.
How do I find my frost dates?
Enter your ZIP code in the Plant Anywhere frost date finder for dates based on 30-year NOAA averages.
Can I plant before my last frost date?
Yes, for cool-season crops that tolerate light frost. Plant 2 to 4 weeks before last frost.
How to protect plants from late frost?
Cover with row cover or sheets before sunset. Water soil in afternoon. Row cover gives 2 to 8 degrees protection.
Frost vs. freeze?
Light frost: 32 to 36 F, damages tender crops. Hard freeze: below 28 F, damages most plants.