Monmouth township Flag

Monmouth township

County:
Warren County
County Seat:
No
Area (mi²):
36.831
State:
Illinois

Monmouth township is located in Warren County, Illinois. Monmouth township has a 2026 population of 9,672. Monmouth township is currently growing at a rate of 0.76% annually but its population has decreased by -2.84% since the most recent census, which recorded a population of 9,955 in 2020.

The median household income in Monmouth township is $61,897 with a poverty rate of 16.66%. The median age in Monmouth township is 35.7 years: 34.1 years for males, and 38 years for females. For every 100 females there are 94.8 males.

9.7K
Total Population
263
Density (mi²)
73 0.76%
Growth

Monmouth township Population

Monmouth township Population

Year ↓
Population
Growth
Annual Change
20269,672730.76%
20259,599730.77%
20249,526-1-0.01%
20239,527-66-0.69%
20229,593-241-2.45%
20219,834-121-1.22%
20209,955-5-0.05%
20199,880-93-0.93%
20189,973-93-0.92%
201710,066-90-0.89%
201610,156-134-1.3%
201510,290-143-1.37%
201410,433290.28%
201310,404-72-0.69%
201210,476-86-0.81%
201110,562990.95%
201010,46740.04%

Median Age

Overall: 35.7 years
Female: 38 years
Male: 34.1 years

Monmouth township Adults

There are 7,467 adults, (1,841 of whom are seniors) in Monmouth township.

Sex Ratio

Female: 4,993 (51.3%)
Male: 4,734 (48.7%)

Demographics

The racial composition of Monmouth township includes 75.16% White, 7.86% other race, 3.94% Black or African American, 3.65% Asian, and smaller percentages for Native American, Native Hawaiian or Pacific Islander and multiracial populations.

Population by Race

Race
Population ↓
Percentage (of total)
White7,31175.16%
Other race7657.86%
Two or more races6887.07%
Black or African American3833.94%
Asian3553.65%
Native American1551.59%
Native Hawaiian or Pacific Islander700.72%
Race
Population ↓
Percentage (of total)
Other race7287.48%
Two or more races4344.46%
White2762.84%
Native American1381.42%
Native Hawaiian or Pacific Islander460.47%
Black or African American10.01%
Race
Population ↓
Percentage (of total)
White7,03572.32%
Black or African American3823.93%
Asian3553.65%
Two or more races2542.61%
Other race370.38%
Native Hawaiian or Pacific Islander240.25%
Native American170.17%

Monmouth township Marital Status

Economics and Income Statistics

Monmouth township's average per capita income is $41,022. Household income levels show a median of $61,897. The poverty rate stands at 16.66%.

Families: A family includes the owner or renter of the home along with everyone related to them - whether through birth, marriage, or adoption. This includes relatives like spouses, children, parents, siblings, grandparents, and any other family members.
Households: A household includes all the people who occupy a housing unit (such as a house or apartment) as their usual place of residence.
Non Families: A nonfamily household is either someone living alone or when the owner/renter lives with people they aren't related to, like roommates.
Name
Median ↓
Mean
Married Families$96,425-
Families$78,453$89,780
Households$61,897$81,648
Non Families$36,652$59,617

$41,022

Average Income

$61,897

Median Household Income

16.66%

Poverty Rate

Sources

  1. US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
  2. US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
  3. American Community Survey (2009 - 2013)
  4. Census QuickFacts
  5. Historical Populations of States and Counties (1790 - 1990)