Allyn is located in Mason county Washington with a geographic area of 1.6 square miles. The total population in Allyn is 2,504 with 53.6% male and 46.4% female. Children under age 5 represent 0.0% of the population, under age 18 equal 16.9% of the population and over age 65 is 28.8% of the population. The median household income is $84,531, per capita income is $40,319. There are a total of 1,053 housing units with 87.3% owner occupied. Education includes 9.5% of residents that are high school graduates and 29.3% with a bachelor's degree or higher. The average temperature in Allyn in the summer is 60 degrees, and in the winter 42 degrees.