Seatac is located in King county Washington with a geographic area of 10.1 square miles. The total population in Seatac is 29,102 with 54.4% male and 45.6% female. Children under age 5 represent 7.3% of the population, under age 18 equal 23.7% of the population and over age 65 is 11.7% of the population. The median household income is $66,131, per capita income is $29,344. There are a total of 10,372 housing units with 48.9% owner occupied. Education includes 24.5% of residents that are high school graduates and 23.9% with a bachelor's degree or higher. The average temperature in Seatac in the summer is 60 degrees, and in the winter 42 degrees.