USDA Plant Hardiness Zone Locator
The regional climate, or at least the regional temperature range, can be determined by referring to the USDA Plant Hardiness Zone Map below. The easiest way to calculate your zone is to go directly to the USDA Plant Hardiness Zone Locator and enter in your zip code. There are other options for maps available off the site as well, but the zip code locator is the easiest way to get your exact zone.
Canadian Plant Hardiness Zone Locator
If you are in Canada you can follow this link to current Plant Hardines Zone map: