Hartly is located in Kent county Delaware with a geographic area of 0.1 square miles. The total population in Hartly is 167 with 68.9% male and 31.1% female. Children under age 5 represent 0.6% of the population, under age 18 equal 10.8% of the population and over age 65 is 1.8% of the population. The median household income is $125,949, per capita income is $45,990. There are a total of 67 housing units with 98.5% owner occupied. Education includes 10.4% of residents that are high school graduates and 1.5% with a bachelor's degree or higher. The average temperature in Hartly in the summer is 74 degrees, and in the winter 35 degrees.