Frost Date Chart: First and Last Frost Dates Across North America

The chart below includes average frost dates for various cities across the U.S. Find the cities near you for good estimate for your frost dates. These dates can vary year by year, usually within about a two-week window.

• First Fall Frost Date - when to expect the end of the gardening season in Fall
• Last Spring Frost Date - when to expect the start of the gardening season in Spring

Understanding Your Growing Season: Light Frost vs. "Killing Frost," "Hard Frost," or "Freeze"

When late fall arrives, you may start to see frost on the ground when you look out the window in the morning. Depending on how cold it is, you may see some frost before you see a freeze. What's the difference?

• A frost (ice crystals forming on surfaces) generally happens when the air temperature is between 36-32 degrees F. 
• A freeze happens when air temperature dips below 32 degrees F. The colder it gets, the more damage you'll see to annual and perennial plants. A hard freeze is usually between 28-25 degrees F, and a killing freeze is 24 degrees F and below. 

In the fall, we'll ship perennial plants and flower bulbs to you at the right time to plant in your zone!

When planting Wildflower seeds in the fall, plant after a killing freeze. That way, seeds can follow their natural course of germinating and sprouting the following spring.

Please note - the dates below are an average that can be used to estimate the timing of your garden - but it's important to keep track of your local weather!

For more details, try looking up your zip code for frost and freeze dates using the lookup tool at Dave's Garden.

Soil temperature is a helpful piece of information in gardening, too. Wildflower seeds typically germinate when the soil is above 55°F, and many plants will wait for soil temperatures to rise to wake up from winter dormancy. Soil temperature is different than air temperature. Look up your soil temperature with GreenCast.

How to Prepare For Frost

With a killing frost, tender annuals are killed down, and while perennials do better, their leaves, buds, and blooms are usually damaged. Some fall wildflowers are exceptions, with special traits that keep them blooming so they can fulfill their botanical objective of ripening their flowers into seeds. Many sunflowers and asters are in this group, often blooming right through the first frosts.

Does Frost Make the Leaves Turn?

No. The changing color of leaves during fall is a completely separate phenomenon from the falling temperatures. Leaf color change is caused by the shortening days as we go from summer into fall. Interestingly, the brilliant fall color is there all summer, but until fall, it is hidden by the production of (green) chlorophyll. As days shorten in fall, leaves shut down their chlorophyll production, and their real pigments are revealed.