Kelso is located in Cowlitz county Washington with a geographic area of 8.1 square miles. The total population in Kelso is 12,237 with 51.5% male and 48.5% female. Children under age 5 represent 6.7% of the population, under age 18 equal 21.5% of the population and over age 65 is 13.7% of the population. The median household income is $48,005, per capita income is $23,067. There are a total of 5,004 housing units with 55.1% owner occupied. Education includes 29.6% of residents that are high school graduates and 11.5% with a bachelor's degree or higher. The average temperature in Kelso in the summer is 63 degrees, and in the winter 42 degrees.
