Find your heat and hardiness (cold) zones. You can even find your soil zone here as well as historic weather data.
Heat Zone Map
Community Collaborative Rain, Hail & Snow Network
Official website of CoCoRaHS providing info on the organization and weather and climate data collected by volunteers all over the country. Some AAEMG members participate in this activity.
National Climatic Data Center (NOAA)
An archive of climate data, maintained by the National Oceanic and Atmospheric Administration (NOAA)
Plant Hardiness Zone Map
Soil Survey Maps
Get a soil survey map of specific areas of the country using this website
Sunset Climate Zones Map
Climate zones used by Sunset in its gardening publications which are popular in the SW.