Because of its location in the higher elevations of northwestern New Jersey's Appalachian mountains, Sussex County has a cooler humid continental climate or microthermal climate (Köppen Dfb) which indicates patterns of significant precipitation in all seasons and at least four months where the average temperature rises above 10 °C The determination of Dfb (warm summer subtype) region is from Peel, M. C., Finlayson, B. L., and McMahon, T. A. (University of Melbourne). [