Middletown is located at . According to the United States Census Bureau, the city has a total area of, all land.
Demographics
2010 census
At the 2010 census there were 318 people in 127 households, including 94 families, in the city. The population density was. There were 148 housing units at an average density of. The racial makup of the city was 95.3% White, 1.6% African American, 1.6% Asian, 0.9% Pacific Islander, and 0.6% from two or more races. Hispanic or Latino of any race were 1.3%. Of the 127 households 34.6% had children under the age of 18 living with them, 58.3% were married couplesliving together, 9.4% had a female householder with no husband present, 6.3% had a male householder with no wife present, and 26.0% were non-families. 22.8% of households were one person and 7.8% were one person aged 65 or older. The average household size was 2.50 and the average family size was 2.88. The median age was 37.5 years. 27.4% of residents were under the age of 18; 5.6% were between the ages of 18 and 24; 26.6% were from 25 to 44; 27% were from 45 to 64; and 13.2% were 65 or older. The gender makeup of the city was 50.9% male and 49.1% female.
At the 2000 census there were 535 people in 191 households, including 141 families, in the city. The population density was 875.2 people per square mile. There were 223 housing units at an average density of 364.8 per square mile. The racial makup of the city was 93.27% White, 2.62% African American, 1.31% Asian, 1.50% from other races, and 1.31% from two or more races. Hispanic or Latino of any race were 2.43%. Of the 191 households 41.4% had children under the age of 18 living with them, 48.7% were married couples living together, 18.3% had a female householder with no husband present, and 25.7% were non-families. 18.8% of households were one person and 4.7% were one person aged 65 or older. The average household size was 2.62 and the average family size was 2.92. Age spread: 28.2% under the age of 18, 7.9% from 18 to 24, 31.4% from 25 to 44, 18.7% from 45 to 64, and 13.8% 65 or older. The median age was 36 years. For every 100 females, there were 94.5 males. For every 100 females age 18 and over, there were 89.2 males. The median household income was $37,083 and the median family income was $37,500. Males had a median income of $37,000 versus $19,167 for females. The per capita income for the city was $16,835. About 15.4% of families and 19.5% of the population were below the poverty line, including 28.8% of those under age 18 and 16.0% of those age 65 or over.
