Darby is located in Ravalli county Montana with a geographic area of 0.6 square miles. The total population in Darby is 685 with 53.1% male and 46.9% female. Children under age 5 represent 2.5% of the population, under age 18 equal 14.0% of the population and over age 65 is 18.4% of the population. The median household income is $29,777, per capita income is $17,868. There are a total of 329 housing units with 45.9% owner occupied. Education includes 35.3% of residents that are high school graduates and 15.5% with a bachelor's degree or higher. The average temperature in Darby in the summer is 69 degrees, and in the winter 27 degrees.