St. john is located in Whitman county Washington with a geographic area of 0.7 square miles. The total population in St. john is 612 with 45.3% male and 54.7% female. Children under age 5 represent 5.1% of the population, under age 18 equal 22.4% of the population and over age 65 is 29.7% of the population. The median household income is $56,563, per capita income is $22,691. There are a total of 239 housing units with 76.2% owner occupied. Education includes 21.8% of residents that are high school graduates and 25.5% with a bachelor's degree or higher. The average temperature in St. john in the summer is 60 degrees, and in the winter 42 degrees.