Let's face it, the only hardiness zone we're usually interested in is our own. Each state has an individual map that shows the gradual changes in hardiness from one area to another. There is also the interactive map
where you can click on the map and get your zone, actual average temperature, the temperature range for your zone and your longitude and latitude. And they included a Zip Code Lookup at the top of the page. Pop in your zip code and out pops your new zone.
Here's the link where you can download all the individual state maps.
Hardiness Zones for Other Countries
Both Canada and Mexico were included in the 1990 Plant Hardiness Zone Mapping. Canada has released their map, but there is currently no new map available for Mexico.
Hardiness Zones Around the World