Griswold is located in New london county Connecticut with a geographic area of square miles. The total population in Griswold is 11,627 with 50.8% male and 49.2% female. Children under age 5 represent 5.2% of the population, under age 18 equal 20.1% of the population and over age 65 is 19.5% of the population. The median household income is $62,361, per capita income is $35,144. There are a total of 5,279 housing units with 75.9% owner occupied. Education includes 29.1% of residents that are high school graduates and 16.4% with a bachelor's degree or higher. The average temperature in Griswold in the summer is 68 degrees, and in the winter 27 degrees.