Belfair is located in Mason county Washington with a geographic area of 7.4 square miles. The total population in Belfair is 4,557 with 55.5% male and 44.5% female. Children under age 5 represent 4.1% of the population, under age 18 equal 20.8% of the population and over age 65 is 13.5% of the population. The median household income is $52,917, per capita income is $26,936. There are a total of 1,838 housing units with 76.1% owner occupied. Education includes 25.2% of residents that are high school graduates and 11.1% with a bachelor's degree or higher. The average temperature in Belfair in the summer is 60 degrees, and in the winter 42 degrees.