HARDINESS GUIDE UNITED STATES

This Map is provided by the United States Department of Agriculture, Yes there are apparently flaws with the map due to snowfall and other seasonal factors but it is the most up to date map there is and can be found on the USDA's website in a bigger version with state and zip code search. The link is listed below to help you.

planthardiness.ars.usda.gov/PHZMWeb/Default.aspx