New Jersey is divided into seven different Zones according to USDA Hardiness Zone map. This map divides all of North America into 11 separate climatic regions based on average annual extreme temperatures. A zone map was first published by the United States Department of Agriculture (USDA) in 1913 and revised every ten years until 2017. Zone 7a is one of these zones in New Jersey. Zone 7a extends from 32° north latitude to 40° north latitude and from 73° west longitude to 76° west longitude. This zone extends from Lake Ontario in the west to Long Island Sound in the east and from central New Jersey in the north to southern New Jersey in the south.