Altmar is located in Oswego county New york with a geographic area of 2.1 square miles. The total population in Altmar is 289 with 52.9% male and 47.1% female. Children under age 5 represent 13.5% of the population, under age 18 equal 26.6% of the population and over age 65 is 8.3% of the population. The median household income is $48,864, per capita income is $19,909. There are a total of 100 housing units with 66.0% owner occupied. Education includes 45.0% of residents that are high school graduates and 10.0% with a bachelor's degree or higher. The average temperature in Altmar in the summer is 70 degrees, and in the winter 27 degrees.