The following comment from Melissa was made to a post discussing the importance of choosing the correct time to plant vegetables inquired into the best way to determine frost free dates: “How do I find out when the frost/freeze danger is over for my area?”
Many gardeners are curious about their last spring and first fall frost dates in order to determine the window for growing frost sensitive plants, and to determine the length of their growing season. They also want to make sure that they don’t plant frost tender plants like tomatoes and peppers until all danger of frost has passed.
Of course the frost free dates vary widely depending on your growing region and even the specific conditions surrounding your landscape and the orientation of your garden.
For example if your garden is situated on a southern facing slope or close to a large body of water you may benefit from natural frost protection that others in your growing region don’t enjoy and be able to safely plant warm weather crops earlier without fear of damage.
The web site at the following link offers a list of frost free dates for selected cities throughout the United States: USA Frost Free Schedule. If your city isn’t listed use the closest location and add or subtract days depending on whether you are further north or south.
Another good reference for obtaining frost free dates in your local area is to contact your Cooperative Extension Service, they usually can provide you with the average date of the last spring frost date for your area.