| The US maps and Canadian maps are a bit different but for the most part quite similar. The CDN one supposedly takes more into account than just the coldest winter temperatures. I am including a link of the USDA hardiness map. The map extends into Southern parts of Canada. Maybe you can visually find your location on the map? If not, you might be able to tell what your USDA zone is based on the lowest winter temperature in your location (on average). There is a chart provided. For example, if your lowest winter temperature (we’re talking temperatures, not windchill) is normally -29 to -32 C (-25 to -20F), then the USDA chart says zone 4B. In summary though, it's not always 100% clear. Some zone 4 stuff has been known to survive in zone 3, especially a sheltered spot. |
Here is a link that might be useful: USDA zone ratings
