Mount Airy is located at 39°22'29" North, 77°9'20" West (39.374798, -77.155678)1.
According to the United States Census Bureau, the town has a total area of 9.9 km² (3.8 mi²). None of the area is covered with water.
As of the census of 2000, there are 6,425 people, 2,123 households, and 1,717 families residing in the town. The population density is 647.7/km² (1,678.5/mi²). There are 2,179 housing units at an average density of 219.7/km² (569.3/mi²). The racial makeup of the town is 94.71% White, 2.58% African American, 0.23% Native American, 0.87% Asian, 0.00% Pacific Islander, 0.25% from other races, and 1.35% from two or more races. 1.34% of the population are Hispanic or Latino of any race.
There are 2,123 households out of which 51.4% have children under the age of 18 living with them, 69.0% are married couples living together, 8.5% have a female householder with no husband present, and 19.1% are non-families. 14.9% of all households are made up of individuals and 5.2% have someone living alone who is 65 years of age or older. The average household size is 3.02 and the average family size is 3.37.
In the town the population is spread out with 34.4% under the age of 18, 5.4% from 18 to 24, 37.1% from 25 to 44, 16.9% from 45 to 64, and 6.2% who are 65 years of age or older. The median age is 33 years. For every 100 females there are 98.5 males. For every 100 females age 18 and over, there are 93.2 males.
The median income for a household in the town is $66,967, and the median income for a family is $76,214. Males have a median income of $52,177 versus $35,054 for females. The per capita income for the town is $25,380. 3.3% of the population and 2.0% of families are below the poverty line. Out of the total people living in poverty, 4.4% are under the age of 18 and 1.8% are 65 or older.
In 2002, local resident James Holt launched a last-minute write-in campaign for the office of mayor against incument Jerry Johnson. Because any voters simply wrote "Holt", the Board of Elections refused to count these votes citing concerns that the votes were for a different "Holt". After appealing the results to a state election board, the votes were ordered to be counted and Mr. Holt won the election.