Allendale is located in Bergen county New jersey with a geographic area of 3.1 square miles. The total population in Allendale is 6,757 with 45.5% male and 54.5% female. Children under age 5 represent 6.0% of the population, under age 18 equal 30.4% of the population and over age 65 is 15.0% of the population. The median household income is $157,958, per capita income is $82,671. There are a total of 2,235 housing units with 76.7% owner occupied. Education includes 6.2% of residents that are high school graduates and 77.3% with a bachelor's degree or higher. The average temperature in Allendale in the summer is 73 degrees, and in the winter 34 degrees.