It’s taken more than a decade, but the US Department of Agriculture (USDA) has finally released an updated Plant Hardiness Zone Map that spans the nation and the territory of Puerto Rico in such detail that gardeners can now zoom right into their local areas.
While (imo) long overdue, the updated USDA Hardiness Zone map is just average lowest temperature. It's good to have that as a data point, but I think it's better utilized when cross referenced with something like the Köppen classification system - my preferred version of this is the Trewartha classification system.