South El Monte first appeared as a city in the1960 U.S. census as part of the Upper San Gabriel Valley census county division.
South El Monte city, California – Racial and ethnic composition Note: the US Census treats Hispanic/Latino as an ethnic category. This table excludes Latinos from the racial categories and assigns them to a separate category. Hispanics/Latinos may be of any race.
The census reported that 99.6% of the population lived in households, 0.3% lived in non-institutionalized group quarters, and 0.1% were institutionalized.[29]
There were 4,921 households, out of which 47.9% included children under the age of 18, 49.0% were married-couple households, 7.3% werecohabiting couple households, 25.3% had a female householder with no partner present, and 18.5% had a male householder with no partner present. 11.0% of households were one person, and 4.9% were one person aged 65 or older. The average household size was 3.96.[29] There were 4,103families (83.4% of all households).[30]
The age distribution was 23.7% under the age of 18, 10.3% aged 18 to 24, 28.1% aged 25 to 44, 25.0% aged 45 to 64, and 12.9% who were 65years of age or older. The median age was 35.6years. For every 100 females, there were 100.7 males.[29]
There were 5,058 housing units at an average density of 1,778.5 units per square mile (686.7 units/km2), of which 4,921 (97.3%) were occupied. Of these, 46.6% were owner-occupied, and 53.4% were occupied by renters.[29]
In 2023, the US Census Bureau estimated that the median household income was $67,153, and theper capita income was $22,743. About 19.2% of families and 23.7% of the population were below the poverty line.[31]
At the2010 census South El Monte had a population of 20,116. The population density was 7,061.5 inhabitants per square mile (2,726.5/km2). The racial makeup of South El Monte was 10,136 (50.4%) White (3.4% Non-Hispanic White), 107 (0.5%) African American, 250 (1.2%) Native American, 2,211 (11.0%) Asian, 12 (0.1%) Pacific Islander, 6,718 (33.4%) from other races, and 682 (3.4%) from two or more races. Hispanic or Latino of any race were 17,079 persons (84.9%).[32][33]
The census reported that 20,059 people (99.7% of the population) lived in households, 47 (0.2%) lived in non-institutionalized group quarters, and 10 (0%) were institutionalized.
There were 4,569 households, 2,643 (57.8%) had children under the age of 18 living in them, 2,554 (55.9%) wereopposite-sex married couples living together, 925 (20.2%) had a female householder with no husband present, 524 (11.5%) had a male householder with no wife present. There were 329 (7.2%)unmarried opposite-sex partnerships, and 21 (0.5%)same-sex married couples or partnerships. 397 households (8.7%) were one person and 208 (4.6%) had someone living alone who was 65 or older. The average household size was 4.39. There were 4,003 families (87.6% of households); the average family size was 4.45.
The age distribution was 6,041 people (30.0%) under the age of 18, 2,323 people (11.5%) aged 18 to 24, 5,894 people (29.3%) aged 25 to 44, 4,062 people (20.2%) aged 45 to 64, and 1,796 people (8.9%) who were 65 or older. The median age was 30.4 years. For every 100 females, there were 101.9 males. For every 100 females age 18 and over, there were 101.2 males.
There were 4,711 housing units at an average density of 1,653.7 per square mile, of the occupied units 2,208 (48.3%) were owner-occupied and 2,361 (51.7%) were rented. The homeowner vacancy rate was 0.7%; the rental vacancy rate was 3.5%. 9,304 people (46.3% of the population) lived in owner-occupied housing units and 10,755 people (53.5%) lived in rental housing units.
According to the 2010 United States Census, South El Monte had a median household income of $44,104, with 19.4% of the population living below the federal poverty line.[32]