Since I use these numbers ( zones ? to zone ? ) to describe where certain plants will grow - these are the maps that correspond with those numberic digits.
This map is based upon average yearly extreme minimum temperatures and may be influenced on a local scale by urbanization and elevation
North America
http://www.usna.usda.gov/Hardzone/ushzmap.html
Europe
http://www.backyardgardener.com/zone/europe1zone.html
http://www.gardenweb.com/zones/europe/
China
http://www.backyardgardener.com/zone/china.html
