Washington is located in District of columbia county District of columbia with a geographic area of 61.1 square miles. The total population in Washington is 701,974 with 47.5% male and 52.5% female. Children under age 5 represent 6.4% of the population, under age 18 equal 18.0% of the population and over age 65 is 12.2% of the population. The median household income is $90,842, per capita income is $58,659. There are a total of 288,307 housing units with 42.5% owner occupied. Education includes 14.1% of residents that are high school graduates and 63.6% with a bachelor's degree or higher. The average temperature in Washington in the summer is 79 degrees, and in the winter 40 degrees.