Knowing the climate of the area you live in can be very helpful when growing plants.
First frost date means the earliest date frost can be expected. The date is important. It determines the last date which many plants can be harvested without damage. The date can vary considerably. The best way to check “first frost date” in your area is to go to the National Arboretum website for a cold-hardiness zone map.
Last frost date means the latest date frost can be expected. In higher elevations or more northern parts of the hemisphere, the date will be in late spring. In lower or more southern regions, the date can vary from late January to early spring. In tropical regions it may never occur,
Last frost date of the year is the “time marker” for the beginning of the growing season for most plants and all except the most hardy vegetables. First frost date is the marker for the end of the growing season.
A guide for first and last frost dates for each zone:
Zone 1:
- Last Frost Date: June 15
- First Frost Date: July 15
- Frost-free days: 30 (But freezes or frosts can occur at any time during the year)
Zone 2:
- Last Frost Date: May 15
- First Frost Date: August 15
- Frost-free days: 90
Zone 3:
- Last Frost Date: May 15
- First Frost Date: September 15
- Frost-free days: 120
Zone 4:
- Last Frost Date: May 15
- First Frost Date: September 15
- Frost-free days: 120
Zone 5:
- Last Frost Date: April 15
- First Frost Date: October 15
- Frost-free days: 180
Zone 6:
- Last Frost Date: April 15
- First Frost Date: October 15
- Frost-free days: 180
Zone 7:
- Last Frost Date: April 15
- First Frost Date: October 15
- Frost-free days: 180
Zone 8:
- Last Frost Date: March 15
- First Frost Date: November 15
- Frost-free days: 240
Zone 9:
- Last Frost Date: February 15
- First Frost Date: December 15
- Frost-free days: 300
Zone 10:
- Last Frost Date: January 31
- First Frost Date: December 15
- Frost-free days: 315
Zone 11:
- There are no first and last frost dates in Zone 11
- Frost-free days: 365
