Thornton is located in Grafton county New hampshire with a geographic area of square miles. The total population in Thornton is 2,520 with 58.2% male and 41.8% female. Children under age 5 represent 4.1% of the population, under age 18 equal 17.0% of the population and over age 65 is 16.5% of the population. The median household income is $74,583, per capita income is $35,457. There are a total of 1,024 housing units with 81.5% owner occupied. Education includes 23.7% of residents that are high school graduates and 40.8% with a bachelor's degree or higher. The average temperature in Thornton in the summer is 68 degrees, and in the winter 23 degrees.