Mercedes is located in Hidalgo county Texas with a geographic area of 11.8 square miles. The total population in Mercedes is 16,561 with 48.3% male and 51.7% female. Children under age 5 represent 8.2% of the population, under age 18 equal 29.0% of the population and over age 65 is 16.3% of the population. The median household income is $39,734, per capita income is $17,578. There are a total of 4,834 housing units with 64.6% owner occupied. Education includes 25.2% of residents that are high school graduates and 13.5% with a bachelor's degree or higher. The average temperature in Mercedes in the summer is 84 degrees, and in the winter 49 degrees.