According to the United States Census Bureau, the CDP has a total area of 1.8 square miles (4.7 km2), of which 1.8 square miles (4.7 km2) is land and 0.56% is water.[3]
As of the census[5] of 2020, there were 12,238 people, 4,110 households, and 3,386 families residing in the CDP. The population density was 7,119.3 inhabitants per square mile (2,748.8/km2). There were 4,221 housing units at an average density of 2454.0/sq mi (947.5/km2). As of 2023, the racial makeup of the CDP was 82.28% White, 4.1% African American, 0.0% Native American, 3.06% Asian, 0.0% Pacific Islander, 0.29% from other races, and 0.83% from two or more races. Hispanic or Latino of any race were 9.44% of the population.[6]
In 2020, there were 4,110 households, out of which 36.1% had children under the age of 18 living with them, 83.2% were married couples living together, 8.4% had a female householder with no husband present, and 21.4% were non-families. The average household size was 3.35 and the average family size was 3.33.[6]
In the CDP, the population was spread out, with 21.5% under the age of 18, 6.4% from 18 to 24, 24.9% from 25 to 44, 27.5% from 45 to 64, and 19.7% who were 65 years of age or older. The median age was 42.7 years. 49.4% of the population is female, and 50.6% of the population is male.
The median income for a household in the CDP was $134,439, and the median income for a family was $143,611. Males had a median income of $66,799 versus $44,012 for females. The per capita income for the CDP was $53,533. About 2.4% of families and 3.0% of the population were below the poverty line, including 2.8% of those under age 18 and 4.3% of those age 65 or over.
North Merrick is protected by a volunteer fire department that is responsible for one of the smallest fire districts in Nassau County covering 2.1 square miles (5.4 km2).[8] The North Merrick Fire Department has approximately 85 members using 16 pieces of apparatus located at one station.[9]
The North Merrick Fire Department's headquarters in May 2022.