Monmouth is a city located in Henderson County and Warren County Illinois. Monmouth has a 2024 population of 8,405. It is also the county seat of Warren County. Monmouth is currently declining at a rate of -1.43% annually and its population has decreased by -5.51% since the most recent census, which recorded a population of 8,895 in 2020.
The average household income in Monmouth is $72,895 with a poverty rate of 18.46%. The median rental costs in recent years comes to - per month, and the median house value is -. The median age in Monmouth is 36 years, 33.3 years for males, and 38.3 years for females.
According to the most recent ACS, the racial composition of Monmouth was:
White
Other race
Black or African American
Two or more races
Asian
Native American
Native Hawaiian or Pacific Islander
Household Type | Count | Average Size | Owner | Renter |
|---|---|---|---|---|
| All | 3,319 | 2.36 | 69.3 | 30.7 |
| Married | 1,320 | 2.98 | 87.6 | 12.4 |
| Non Family | 1,159 | 1.15 | 55.8 | 44.2 |
| Female | 602 | 3.32 | 63.5 | 36.5 |
| Male | 238 | 2.34 | 48.7 | 51.3 |
2.9
Average Family Size
2.36
Average Household Size
69.3%
Rate of Home Ownership
Married
Male
Female
NonFamily
owner
renter
Male
Female
Less Than 9th Grade
9th to 12th Grade
High School Graduate
Some College
Associates Degree
Bachelors Degree
Graduate Degree
High School Graduation Rate
Bachelors Rate
The highest rate of high school graduation is among islander people with a rate of 100%.
The highest rate of bachelors degrees is among white people with a rate of 22.36%.
All
Male
Female
$38,584
Average Earnings
$50,464
Average Male
$31,000
Average Female
Only English
Spanish
Other Indo-European Languages
Asian and Pacific Island Languages
Other Languages
81.17% of Monmouth residents speak only English, while 18.83% speak other languages. The non-English language spoken by the largest group is Spanish, which is spoken by 12.66% of the population.
rate
18.46%
Overall Poverty Rate
18.11%
Male Poverty Rate
18.79%
Female Poverty Rate
The race most likely to be in poverty in Monmouth is Native, with 74.85% below the poverty level.
The race least likely to be in poverty in Monmouth is Black, with 1.42% below the poverty level.
The poverty rate among those that worked full-time for the past 12 months was 2.15%. Among those working part-time, it was 17.39%, and for those that did not work, the poverty rate was 26.5%.
Married
Widowed
Divorced
Separated
NeverMarried
38.3%
Overall Marriage Rate
42.6%
Male Marriage Rate
34.7%
Female Marriage Rate
male
female
The age group where males are most likely to be married is Over 65, while the female age group most likely to be married is 45-54.
Married
Widowed
Divorced
Separated
NeverMarried
Less Than 9th Grade
High School Graduate
Some College
Bachelors or Greater
1.12%
Veteran Poverty Rate
38.27%
Veteran Disability Rate
LaborForceParticipation
61.8%
Labor Force Participation
55.2%
Employment Rate
10.7%
Unemployment Rate
LaborForceParticipation
LaborForceParticipation
Europe
Asia
Africa
Oceania
Latin America
North America
Non citizens include legal permanent residents (green card holders), international students, temporary workers, humanitarian migrants, and illegal immigrants.
Europe
Asia
Africa
Oceania
Latin America
North America
63.16%
Born in Monmouth
88.53%
Native Born
11.47%
Foreign Born
5.79%
Non Citizen
5.68%
Naturalized
88.53% of Monmouth residents were born in the United States, with 63.16% having been born in Illinois. 5.79% of residents are not US citizens. Of those not born in the United States, the largest percentage are from Latin America.
Year | Population | Growth | Growth Rate |
|---|---|---|---|
| 2029 | 7,792 | -123 | -1.55% |
| 2028 | 7,915 | -122 | -1.52% |
| 2027 | 8,037 | -123 | -1.51% |
| 2026 | 8,160 | -122 | -1.47% |
| 2025 | 8,282 | -123 | -1.46% |
| 2024 | 8,405 | -122 | -1.43% |
| 2023 | 8,527 | -123 | -1.42% |
| 2022 | 8,650 | -121 | -1.38% |
| 2021 | 8,771 | -124 | -1.39% |
| 2020 | 8,895 | 25 | 0.28% |
| 2019 | 8,870 | -84 | -0.94% |
| 2018 | 8,954 | -84 | -0.93% |
| 2017 | 9,038 | -83 | -0.91% |
| 2016 | 9,121 | -132 | -1.43% |
| 2015 | 9,253 | -127 | -1.35% |
| 2014 | 9,380 | 25 | 0.27% |
| 2013 | 9,355 | -71 | -0.75% |
| 2012 | 9,426 | -87 | -0.91% |
| 2011 | 9,513 | 89 | 0.94% |
| 2010 | 9,424 | -417 | -4.24% |
| 2000 | 9,841 | 352 | 3.71% |
| 1990 | 9,489 | -1,217 | -11.37% |
| 1980 | 10,706 | -316 | -2.87% |
| 1970 | 11,022 | 650 | 6.27% |
| 1960 | 10,372 | 179 | 1.76% |
| 1950 | 10,193 | 1,097 | 12.06% |
| 1940 | 9,096 | 430 | 4.96% |
| 1930 | 8,666 | 550 | 6.78% |
| 1920 | 8,116 | -1,012 | -11.09% |
| 1910 | 9,128 | 1,668 | 22.36% |
| 1900 | 7,460 | 1,524 | 25.67% |
| 1890 | 5,936 | 936 | 18.72% |
| 1880 | 5,000 | 338 | 7.25% |
| 1870 | 4,662 | 2,156 | 86.03% |
| 1860 | 2,506 | 0 | 0% |