Frost dates play an important role in garden timing. We use them to determine when to start seeds and know when it's safe to transplant tender plants outdoors. Of course, weather patterns vary from year to year and the dates below are based on a 10-year average. There are also microclimates within growing zones, caused by things like urbanization, steep elevation changes, or nearby bodies of water.

The average frost dates are when you can expect the last frost in spring and the first frost in fall.

Zone	Average Last Frost Date	Average First Frost Date
Zone 1	May 22-June 4	August 25-31
Zone 2	May 15-22	September 1-8
Zone 3	May 1-16	September 8-15
Zone 4	April 24-May 12	September 21-October 7
Zone 5	April 7-30	October 13-21
Zone 6	April 1-21	October 17-31
Zone 7	March 22-April 3	October 29-November 15
Zone 8	March 13-28	November 7-28
Zone 9	February 6-28	November 25-December 13
Zone 10-13	No usual frost	No usual frost

Information based on USDA Hardiness Zone Method.

Unsure of your USDA Hardiness Zone? Use this map to determine what zone you're in.

What does last frost date mean?

The last frost date for your location is a good indicator of when it is safe to start planting seeds or seedlings outdoors. It refers to an expected date in spring that’s determined using historical weather data in a given location. Plant after your last frost date to ensure your plants have the best chance of survival.

The last frost date is also important if you’ll be starting seeds indoors. Use it to determine when to start your seeds so that they will be ready to transplant outdoors once your last frost date has passed. In general, start seeds indoors 6-8 weeks before the last expected frost date in your location. This allows your seedlings to grow and develop indoors under controlled conditions until the weather is warm enough for you to transplant them into the garden.

What does first frost date mean?

Your "first frost date" is the approximate date in autumn when the first frost is expected to occur in your location. It is determined using historical weather data and signals the end of the growing season for gardeners.

You need to know the first frost date because frost can be damaging to your plants, especially those that aren’t cold-hardy. By knowing when your first frost is likely to occur, you can take steps to protect your plants or harvest them before the frost hits. Additionally, you can use the first frost date to plan when to plant fall crops that are able to withstand cooler temperatures.