Newcastle is located in King county Washington with a geographic area of 4.4 square miles. The total population in Newcastle is 12,078 with 50.6% male and 49.4% female. Children under age 5 represent 6.8% of the population, under age 18 equal 20.8% of the population and over age 65 is 15.1% of the population. The median household income is $155,933, per capita income is $77,950. There are a total of 4,935 housing units with 76.9% owner occupied. Education includes 5.6% of residents that are high school graduates and 75.1% with a bachelor's degree or higher. The average temperature in Newcastle in the summer is 60 degrees, and in the winter 42 degrees.
