Gretna is located in Sarpy county Nebraska with a geographic area of 2.6 square miles. The total population in Gretna is 5,039 with 45.5% male and 54.5% female. Children under age 5 represent 6.2% of the population, under age 18 equal 25.5% of the population and over age 65 is 13.3% of the population. The median household income is $69,592, per capita income is $36,210. There are a total of 2,020 housing units with 57.4% owner occupied. Education includes 18.7% of residents that are high school graduates and 41.7% with a bachelor's degree or higher. The average temperature in Gretna in the summer is 75 degrees, and in the winter 26 degrees.