Monrovia is located in Los angeles county California with a geographic area of 13.6 square miles. The total population in Monrovia is 37,636 with 48.3% male and 51.7% female. Children under age 5 represent 4.9% of the population, under age 18 equal 21.6% of the population and over age 65 is 13.7% of the population. The median household income is $81,990, per capita income is $37,842. There are a total of 13,322 housing units with 47.3% owner occupied. Education includes 14.5% of residents that are high school graduates and 46.1% with a bachelor's degree or higher. The average temperature in Monrovia in the summer is 76 degrees, and in the winter 43 degrees.