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Sussex NJ is in USDA Hardiness Zone 6a: -10F to -5F. Using updated climate data through 2010, 07461 is in the Plantmaps Hardiness Zone 5b: -15F to -10F. The average first frost in 07461 is between October 1 - 10, while the average last frost occurs between May 1 - 10. 07461 is part of Ecoregion 67k - Northern Glaciated Shale and Slate Valleys. 07461 rarely has days where the temperatue exceeds 86°F. The average annual high temperature in 07461 is 60°F and the average annual low temperature is 37°F. The average high temperature in July (Summer) is 81°F, while the average high temperature in January (Winter) is 34°F.