New 2012 USDA Planting Zones of Southwestern United States
Compare the new 2012 USDA Gardening Zones Map with the older 1990 map below. You will notice some changes in the zone boundaries, some definitely warmer and then some possibly cooler. Overall the new map shows a slight warming trend when compared to the older map which was published by the USDA only 20 years ago!
Familiarize yourself with the new color coding for the individual gardening zones, then see if you live in one of the Southwestern Gardening Zones that has become warmer.
Older 1990 USDA Gardening Zones Map of Southwestern USA is not as detailed as the new 2012 USDA Gardening Zones Map.